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class="yui-b"> <div class="yui-g" id="_modules-django-db-backends-base-schema"> <h1>Source code for django.db.backends.base.schema</h1><div class="highlight"><pre> <span></span><span class="kn">import</span> <span class="nn">hashlib</span> <span class="kn">from</span> <span class="nn">django.db.backends.utils</span> <span class="k">import</span> <span class="n">truncate_name</span> <span class="kn">from</span> <span class="nn">django.db.transaction</span> <span class="k">import</span> <span class="n">atomic</span> <span class="kn">from</span> <span class="nn">django.utils</span> <span class="k">import</span> <span class="n">six</span> <span class="kn">from</span> <span class="nn">django.utils.encoding</span> <span class="k">import</span> <span class="n">force_bytes</span> <span class="kn">from</span> <span class="nn">django.utils.log</span> <span class="k">import</span> <span class="n">getLogger</span> <span class="n">logger</span> <span class="o">=</span> <span class="n">getLogger</span><span class="p">(</span><span class="s1">'django.db.backends.schema'</span><span class="p">)</span> <span class="k">def</span> <span class="nf">_related_non_m2m_objects</span><span class="p">(</span><span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">):</span> <span class="c1"># Filters out m2m objects from reverse relations.</span> <span class="c1"># Returns (old_relation, new_relation) tuples.</span> <span class="k">return</span> <span class="nb">zip</span><span class="p">(</span> <span class="p">(</span><span class="n">obj</span> <span class="k">for</span> <span class="n">obj</span> <span class="ow">in</span> <span class="n">old_field</span><span class="o">.</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">related_objects</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">obj</span><span class="o">.</span><span class="n">field</span><span class="o">.</span><span class="n">many_to_many</span><span class="p">),</span> <span class="p">(</span><span class="n">obj</span> <span class="k">for</span> <span class="n">obj</span> <span class="ow">in</span> <span class="n">new_field</span><span class="o">.</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">related_objects</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">obj</span><span class="o">.</span><span class="n">field</span><span class="o">.</span><span class="n">many_to_many</span><span class="p">)</span> <span class="p">)</span> <div class="viewcode-block" id="BaseDatabaseSchemaEditor"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor">[docs]</a><span class="k">class</span> <span class="nc">BaseDatabaseSchemaEditor</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> This class (and its subclasses) are responsible for emitting schema-changing</span> <span class="sd"> statements to the databases - model creation/removal/alteration, field</span> <span class="sd"> renaming, index fiddling, and so on.</span> <span class="sd"> It is intended to eventually completely replace DatabaseCreation.</span> <span class="sd"> This class should be used by creating an instance for each set of schema</span> <span class="sd"> changes (e.g. a syncdb run, a migration file), and by first calling start(),</span> <span class="sd"> then the relevant actions, and then commit(). This is necessary to allow</span> <span class="sd"> things like circular foreign key references - FKs will only be created once</span> <span class="sd"> commit() is called.</span> <span class="sd"> """</span> <span class="c1"># Overrideable SQL templates</span> <span class="n">sql_create_table</span> <span class="o">=</span> <span class="s2">"CREATE TABLE </span><span class="si">%(table)s</span><span class="s2"> (</span><span class="si">%(definition)s</span><span class="s2">)"</span> <span class="n">sql_create_table_unique</span> <span class="o">=</span> <span class="s2">"UNIQUE (</span><span class="si">%(columns)s</span><span class="s2">)"</span> <span class="n">sql_rename_table</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(old_table)s</span><span class="s2"> RENAME TO </span><span class="si">%(new_table)s</span><span class="s2">"</span> <span class="n">sql_retablespace_table</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> SET TABLESPACE </span><span class="si">%(new_tablespace)s</span><span class="s2">"</span> <span class="n">sql_delete_table</span> <span class="o">=</span> <span class="s2">"DROP TABLE </span><span class="si">%(table)s</span><span class="s2"> CASCADE"</span> <span class="n">sql_create_column</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> ADD COLUMN </span><span class="si">%(column)s</span><span class="s2"> </span><span class="si">%(definition)s</span><span class="s2">"</span> <span class="n">sql_alter_column</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> </span><span class="si">%(changes)s</span><span class="s2">"</span> <span class="n">sql_alter_column_type</span> <span class="o">=</span> <span class="s2">"ALTER COLUMN </span><span class="si">%(column)s</span><span class="s2"> TYPE </span><span class="si">%(type)s</span><span class="s2">"</span> <span class="n">sql_alter_column_null</span> <span class="o">=</span> <span class="s2">"ALTER COLUMN </span><span class="si">%(column)s</span><span class="s2"> DROP NOT NULL"</span> <span class="n">sql_alter_column_not_null</span> <span class="o">=</span> <span class="s2">"ALTER COLUMN </span><span class="si">%(column)s</span><span class="s2"> SET NOT NULL"</span> <span class="n">sql_alter_column_default</span> <span class="o">=</span> <span class="s2">"ALTER COLUMN </span><span class="si">%(column)s</span><span class="s2"> SET DEFAULT </span><span class="si">%(default)s</span><span class="s2">"</span> <span class="n">sql_alter_column_no_default</span> <span class="o">=</span> <span class="s2">"ALTER COLUMN </span><span class="si">%(column)s</span><span class="s2"> DROP DEFAULT"</span> <span class="n">sql_delete_column</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> DROP COLUMN </span><span class="si">%(column)s</span><span class="s2"> CASCADE"</span> <span class="n">sql_rename_column</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> RENAME COLUMN </span><span class="si">%(old_column)s</span><span class="s2"> TO </span><span class="si">%(new_column)s</span><span class="s2">"</span> <span class="n">sql_update_with_default</span> <span class="o">=</span> <span class="s2">"UPDATE </span><span class="si">%(table)s</span><span class="s2"> SET </span><span class="si">%(column)s</span><span class="s2"> = </span><span class="si">%(default)s</span><span class="s2"> WHERE </span><span class="si">%(column)s</span><span class="s2"> IS NULL"</span> <span class="n">sql_create_check</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> ADD CONSTRAINT </span><span class="si">%(name)s</span><span class="s2"> CHECK (</span><span class="si">%(check)s</span><span class="s2">)"</span> <span class="n">sql_delete_check</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> DROP CONSTRAINT </span><span class="si">%(name)s</span><span class="s2">"</span> <span class="n">sql_create_unique</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> ADD CONSTRAINT </span><span class="si">%(name)s</span><span class="s2"> UNIQUE (</span><span class="si">%(columns)s</span><span class="s2">)"</span> <span class="n">sql_delete_unique</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> DROP CONSTRAINT </span><span class="si">%(name)s</span><span class="s2">"</span> <span class="n">sql_create_fk</span> <span class="o">=</span> <span class="p">(</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> ADD CONSTRAINT </span><span class="si">%(name)s</span><span class="s2"> FOREIGN KEY (</span><span class="si">%(column)s</span><span class="s2">) "</span> <span class="s2">"REFERENCES </span><span class="si">%(to_table)s</span><span class="s2"> (</span><span class="si">%(to_column)s</span><span class="s2">) DEFERRABLE INITIALLY DEFERRED"</span> <span class="p">)</span> <span class="n">sql_create_inline_fk</span> <span class="o">=</span> <span class="kc">None</span> <span class="n">sql_delete_fk</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> DROP CONSTRAINT </span><span class="si">%(name)s</span><span class="s2">"</span> <span class="n">sql_create_index</span> <span class="o">=</span> <span class="s2">"CREATE INDEX </span><span class="si">%(name)s</span><span class="s2"> ON </span><span class="si">%(table)s</span><span class="s2"> (</span><span class="si">%(columns)s</span><span class="s2">)</span><span class="si">%(extra)s</span><span class="s2">"</span> <span class="n">sql_delete_index</span> <span class="o">=</span> <span class="s2">"DROP INDEX </span><span class="si">%(name)s</span><span class="s2">"</span> <span class="n">sql_create_pk</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> ADD CONSTRAINT </span><span class="si">%(name)s</span><span class="s2"> PRIMARY KEY (</span><span class="si">%(columns)s</span><span class="s2">)"</span> <span class="n">sql_delete_pk</span> <span class="o">=</span> <span class="s2">"ALTER TABLE </span><span class="si">%(table)s</span><span class="s2"> DROP CONSTRAINT </span><span class="si">%(name)s</span><span class="s2">"</span> <span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">collect_sql</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span> <span class="o">=</span> <span class="n">connection</span> <span class="bp">self</span><span class="o">.</span><span class="n">collect_sql</span> <span class="o">=</span> <span class="n">collect_sql</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">collect_sql</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">collected_sql</span> <span class="o">=</span> <span class="p">[]</span> <span class="c1"># State-managing methods</span> <span class="k">def</span> <span class="nf">__enter__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">can_rollback_ddl</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">atomic</span> <span class="o">=</span> <span class="n">atomic</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">alias</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">atomic</span><span class="o">.</span><span class="n">__enter__</span><span class="p">()</span> <span class="k">return</span> <span class="bp">self</span> <span class="k">def</span> <span class="nf">__exit__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exc_type</span><span class="p">,</span> <span class="n">exc_value</span><span class="p">,</span> <span class="n">traceback</span><span class="p">):</span> <span class="k">if</span> <span class="n">exc_type</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span> <span class="k">for</span> <span class="n">sql</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">can_rollback_ddl</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">atomic</span><span class="o">.</span><span class="n">__exit__</span><span class="p">(</span><span class="n">exc_type</span><span class="p">,</span> <span class="n">exc_value</span><span class="p">,</span> <span class="n">traceback</span><span class="p">)</span> <span class="c1"># Core utility functions</span> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.execute"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.execute">[docs]</a> <span class="k">def</span> <span class="nf">execute</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span><span class="o">=</span><span class="p">[]):</span> <span class="sd">"""</span> <span class="sd"> Executes the given SQL statement, with optional parameters.</span> <span class="sd"> """</span> <span class="c1"># Log the command we're running, then run it</span> <span class="n">logger</span><span class="o">.</span><span class="n">debug</span><span class="p">(</span><span class="s2">"</span><span class="si">%s</span><span class="s2">; (params </span><span class="si">%r</span><span class="s2">)"</span> <span class="o">%</span> <span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">params</span><span class="p">))</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">collect_sql</span><span class="p">:</span> <span class="n">ending</span> <span class="o">=</span> <span class="s2">""</span> <span class="k">if</span> <span class="n">sql</span><span class="o">.</span><span class="n">endswith</span><span class="p">(</span><span class="s2">";"</span><span class="p">)</span> <span class="k">else</span> <span class="s2">";"</span> <span class="k">if</span> <span class="n">params</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">collected_sql</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">sql</span> <span class="o">%</span> <span class="nb">tuple</span><span class="p">(</span><span class="nb">map</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">quote_value</span><span class="p">,</span> <span class="n">params</span><span class="p">)))</span> <span class="o">+</span> <span class="n">ending</span><span class="p">)</span> <span class="k">else</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">collected_sql</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">sql</span> <span class="o">+</span> <span class="n">ending</span><span class="p">)</span> <span class="k">else</span><span class="p">:</span> <span class="k">with</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">cursor</span><span class="p">()</span> <span class="k">as</span> <span class="n">cursor</span><span class="p">:</span> <span class="n">cursor</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">params</span><span class="p">)</span></div> <span class="k">def</span> <span class="nf">quote_name</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">name</span><span class="p">):</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">name</span><span class="p">)</span> <span class="nd">@classmethod</span> <span class="k">def</span> <span class="nf">_digest</span><span class="p">(</span><span class="n">cls</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Generates a 32-bit digest of a set of arguments that can be used to</span> <span class="sd"> shorten identifying names.</span> <span class="sd"> """</span> <span class="n">h</span> <span class="o">=</span> <span class="n">hashlib</span><span class="o">.</span><span class="n">md5</span><span class="p">()</span> <span class="k">for</span> <span class="n">arg</span> <span class="ow">in</span> <span class="n">args</span><span class="p">:</span> <span class="n">h</span><span class="o">.</span><span class="n">update</span><span class="p">(</span><span class="n">force_bytes</span><span class="p">(</span><span class="n">arg</span><span class="p">))</span> <span class="k">return</span> <span class="n">h</span><span class="o">.</span><span class="n">hexdigest</span><span class="p">()[:</span><span class="mi">8</span><span class="p">]</span> <span class="c1"># Field <-> database mapping functions</span> <span class="k">def</span> <span class="nf">column_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">,</span> <span class="n">include_default</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Takes a field and returns its column definition.</span> <span class="sd"> The field must already have had set_attributes_from_name called.</span> <span class="sd"> """</span> <span class="c1"># Get the column's type and use that as the basis of the SQL</span> <span class="n">db_params</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="n">sql</span> <span class="o">=</span> <span class="n">db_params</span><span class="p">[</span><span class="s1">'type'</span><span class="p">]</span> <span class="n">params</span> <span class="o">=</span> <span class="p">[]</span> <span class="c1"># Check for fields that aren't actually columns (e.g. M2M)</span> <span class="k">if</span> <span class="n">sql</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span> <span class="k">return</span> <span class="kc">None</span><span class="p">,</span> <span class="kc">None</span> <span class="c1"># Work out nullability</span> <span class="n">null</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">null</span> <span class="c1"># If we were told to include a default value, do so</span> <span class="n">include_default</span> <span class="o">=</span> <span class="n">include_default</span> <span class="ow">and</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">skip_default</span><span class="p">(</span><span class="n">field</span><span class="p">)</span> <span class="k">if</span> <span class="n">include_default</span><span class="p">:</span> <span class="n">default_value</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">effective_default</span><span class="p">(</span><span class="n">field</span><span class="p">)</span> <span class="k">if</span> <span class="n">default_value</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">requires_literal_defaults</span><span class="p">:</span> <span class="c1"># Some databases can't take defaults as a parameter (oracle)</span> <span class="c1"># If this is the case, the individual schema backend should</span> <span class="c1"># implement prepare_default</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" DEFAULT </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">prepare_default</span><span class="p">(</span><span class="n">default_value</span><span class="p">)</span> <span class="k">else</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" DEFAULT </span><span class="si">%s</span><span class="s2">"</span> <span class="n">params</span> <span class="o">+=</span> <span class="p">[</span><span class="n">default_value</span><span class="p">]</span> <span class="c1"># Oracle treats the empty string ('') as null, so coerce the null</span> <span class="c1"># option whenever '' is a possible value.</span> <span class="k">if</span> <span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">empty_strings_allowed</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">interprets_empty_strings_as_nulls</span><span class="p">):</span> <span class="n">null</span> <span class="o">=</span> <span class="kc">True</span> <span class="k">if</span> <span class="n">null</span> <span class="ow">and</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">implied_column_null</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" NULL"</span> <span class="k">elif</span> <span class="ow">not</span> <span class="n">null</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" NOT NULL"</span> <span class="c1"># Primary key/unique outputs</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">primary_key</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" PRIMARY KEY"</span> <span class="k">elif</span> <span class="n">field</span><span class="o">.</span><span class="n">unique</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" UNIQUE"</span> <span class="c1"># Optionally add the tablespace if it's an implicitly indexed column</span> <span class="n">tablespace</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">db_tablespace</span> <span class="ow">or</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_tablespace</span> <span class="k">if</span> <span class="n">tablespace</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">supports_tablespaces</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">unique</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">tablespace_sql</span><span class="p">(</span><span class="n">tablespace</span><span class="p">,</span> <span class="n">inline</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># Return the sql</span> <span class="k">return</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="k">def</span> <span class="nf">skip_default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">field</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Some backends don't accept default values for certain columns types</span> <span class="sd"> (i.e. MySQL longtext and longblob).</span> <span class="sd"> """</span> <span class="k">return</span> <span class="kc">False</span> <span class="k">def</span> <span class="nf">prepare_default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">value</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Only used for backends which have requires_literal_defaults feature</span> <span class="sd"> """</span> <span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">(</span> <span class="s1">'subclasses of BaseDatabaseSchemaEditor for backends which have '</span> <span class="s1">'requires_literal_defaults must provide a prepare_default() method'</span> <span class="p">)</span> <span class="k">def</span> <span class="nf">effective_default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">field</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Returns a field's effective database default value</span> <span class="sd"> """</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">has_default</span><span class="p">():</span> <span class="n">default</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">get_default</span><span class="p">()</span> <span class="k">elif</span> <span class="ow">not</span> <span class="n">field</span><span class="o">.</span><span class="n">null</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">blank</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">empty_strings_allowed</span><span class="p">:</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span> <span class="o">==</span> <span class="s2">"BinaryField"</span><span class="p">:</span> <span class="n">default</span> <span class="o">=</span> <span class="n">six</span><span class="o">.</span><span class="n">binary_type</span><span class="p">()</span> <span class="k">else</span><span class="p">:</span> <span class="n">default</span> <span class="o">=</span> <span class="n">six</span><span class="o">.</span><span class="n">text_type</span><span class="p">()</span> <span class="k">else</span><span class="p">:</span> <span class="n">default</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># If it's a callable, call it</span> <span class="k">if</span> <span class="n">six</span><span class="o">.</span><span class="n">callable</span><span class="p">(</span><span class="n">default</span><span class="p">):</span> <span class="n">default</span> <span class="o">=</span> <span class="n">default</span><span class="p">()</span> <span class="c1"># Run it through the field's get_db_prep_save method so we can send it</span> <span class="c1"># to the database.</span> <span class="n">default</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">get_db_prep_save</span><span class="p">(</span><span class="n">default</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="k">return</span> <span class="n">default</span> <span class="k">def</span> <span class="nf">quote_value</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">value</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Returns a quoted version of the value so it's safe to use in an SQL</span> <span class="sd"> string. This is not safe against injection from user code; it is</span> <span class="sd"> intended only for use in making SQL scripts or preparing default values</span> <span class="sd"> for particularly tricky backends (defaults are not user-defined, though,</span> <span class="sd"> so this is safe).</span> <span class="sd"> """</span> <span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">()</span> <span class="c1"># Actions</span> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.create_model"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.create_model">[docs]</a> <span class="k">def</span> <span class="nf">create_model</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Takes a model and creates a table for it in the database.</span> <span class="sd"> Will also create any accompanying indexes or unique constraints.</span> <span class="sd"> """</span> <span class="c1"># Create column SQL, add FK deferreds if needed</span> <span class="n">column_sqls</span> <span class="o">=</span> <span class="p">[]</span> <span class="n">params</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">local_fields</span><span class="p">:</span> <span class="c1"># SQL</span> <span class="n">definition</span><span class="p">,</span> <span class="n">extra_params</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">column_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">)</span> <span class="k">if</span> <span class="n">definition</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span> <span class="k">continue</span> <span class="c1"># Check constraints can go on the column SQL here</span> <span class="n">db_params</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="k">if</span> <span class="n">db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]:</span> <span class="n">definition</span> <span class="o">+=</span> <span class="s2">" CHECK (</span><span class="si">%s</span><span class="s2">)"</span> <span class="o">%</span> <span class="n">db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="c1"># Autoincrement SQL (for backends with inline variant)</span> <span class="n">col_type_suffix</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">db_type_suffix</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="k">if</span> <span class="n">col_type_suffix</span><span class="p">:</span> <span class="n">definition</span> <span class="o">+=</span> <span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">col_type_suffix</span> <span class="n">params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">extra_params</span><span class="p">)</span> <span class="c1"># FK</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">db_constraint</span><span class="p">:</span> <span class="n">to_table</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">to</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span> <span class="n">to_column</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">to</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">field_name</span><span class="p">)</span><span class="o">.</span><span class="n">column</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">supports_foreign_keys</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_fk_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">,</span> <span class="s2">"_fk_</span><span class="si">%(to_table)s</span><span class="s2">_</span><span class="si">%(to_column)s</span><span class="s2">"</span><span class="p">))</span> <span class="k">elif</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_inline_fk</span><span class="p">:</span> <span class="n">definition</span> <span class="o">+=</span> <span class="s2">" "</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_inline_fk</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"to_table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">to_table</span><span class="p">),</span> <span class="s2">"to_column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">to_column</span><span class="p">),</span> <span class="p">}</span> <span class="c1"># Add the SQL to our big list</span> <span class="n">column_sqls</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="s2">"</span><span class="si">%s</span><span class="s2"> </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="n">definition</span><span class="p">,</span> <span class="p">))</span> <span class="c1"># Autoincrement SQL (for backends with post table definition variant)</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span> <span class="o">==</span> <span class="s2">"AutoField"</span><span class="p">:</span> <span class="n">autoinc_sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">autoinc_sql</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">)</span> <span class="k">if</span> <span class="n">autoinc_sql</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">autoinc_sql</span><span class="p">)</span> <span class="c1"># Add any unique_togethers</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">unique_together</span><span class="p">:</span> <span class="n">columns</span> <span class="o">=</span> <span class="p">[</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">field</span><span class="p">)</span><span class="o">.</span><span class="n">column</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">fields</span><span class="p">]</span> <span class="n">column_sqls</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_create_table_unique</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"columns"</span><span class="p">:</span> <span class="s2">", "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">column</span><span class="p">)</span> <span class="k">for</span> <span class="n">column</span> <span class="ow">in</span> <span class="n">columns</span><span class="p">),</span> <span class="p">})</span> <span class="c1"># Make the table</span> <span class="n">sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_table</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"definition"</span><span class="p">:</span> <span class="s2">", "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">column_sqls</span><span class="p">)</span> <span class="p">}</span> <span class="k">if</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_tablespace</span><span class="p">:</span> <span class="n">tablespace_sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">tablespace_sql</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_tablespace</span><span class="p">)</span> <span class="k">if</span> <span class="n">tablespace_sql</span><span class="p">:</span> <span class="n">sql</span> <span class="o">+=</span> <span class="s1">' '</span> <span class="o">+</span> <span class="n">tablespace_sql</span> <span class="c1"># Prevent using [] as params, in the case a literal '%' is used in the definition</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="ow">or</span> <span class="kc">None</span><span class="p">)</span> <span class="c1"># Add any field index and index_together's (deferred as SQLite3 _remake_table needs it)</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_model_indexes_sql</span><span class="p">(</span><span class="n">model</span><span class="p">))</span> <span class="c1"># Make M2M tables</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">local_many_to_many</span><span class="p">:</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">create_model</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">)</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.delete_model"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.delete_model">[docs]</a> <span class="k">def</span> <span class="nf">delete_model</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Deletes a model from the database.</span> <span class="sd"> """</span> <span class="c1"># Handle auto-created intermediary models</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">local_many_to_many</span><span class="p">:</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">delete_model</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">)</span> <span class="c1"># Delete the table</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_table</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="p">})</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.alter_unique_together"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.alter_unique_together">[docs]</a> <span class="k">def</span> <span class="nf">alter_unique_together</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_unique_together</span><span class="p">,</span> <span class="n">new_unique_together</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Deals with a model changing its unique_together.</span> <span class="sd"> Note: The input unique_togethers must be doubly-nested, not the single-</span> <span class="sd"> nested ["foo", "bar"] format.</span> <span class="sd"> """</span> <span class="n">olds</span> <span class="o">=</span> <span class="nb">set</span><span class="p">(</span><span class="nb">tuple</span><span class="p">(</span><span class="n">fields</span><span class="p">)</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">old_unique_together</span><span class="p">)</span> <span class="n">news</span> <span class="o">=</span> <span class="nb">set</span><span class="p">(</span><span class="nb">tuple</span><span class="p">(</span><span class="n">fields</span><span class="p">)</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">new_unique_together</span><span class="p">)</span> <span class="c1"># Deleted uniques</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">olds</span><span class="o">.</span><span class="n">difference</span><span class="p">(</span><span class="n">news</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">_delete_composed_index</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">fields</span><span class="p">,</span> <span class="p">{</span><span class="s1">'unique'</span><span class="p">:</span> <span class="kc">True</span><span class="p">},</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_unique</span><span class="p">)</span> <span class="c1"># Created uniques</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">news</span><span class="o">.</span><span class="n">difference</span><span class="p">(</span><span class="n">olds</span><span class="p">):</span> <span class="n">columns</span> <span class="o">=</span> <span class="p">[</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">field</span><span class="p">)</span><span class="o">.</span><span class="n">column</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">fields</span><span class="p">]</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_unique_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">columns</span><span class="p">))</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.alter_index_together"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.alter_index_together">[docs]</a> <span class="k">def</span> <span class="nf">alter_index_together</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_index_together</span><span class="p">,</span> <span class="n">new_index_together</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Deals with a model changing its index_together.</span> <span class="sd"> Note: The input index_togethers must be doubly-nested, not the single-</span> <span class="sd"> nested ["foo", "bar"] format.</span> <span class="sd"> """</span> <span class="n">olds</span> <span class="o">=</span> <span class="nb">set</span><span class="p">(</span><span class="nb">tuple</span><span class="p">(</span><span class="n">fields</span><span class="p">)</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">old_index_together</span><span class="p">)</span> <span class="n">news</span> <span class="o">=</span> <span class="nb">set</span><span class="p">(</span><span class="nb">tuple</span><span class="p">(</span><span class="n">fields</span><span class="p">)</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">new_index_together</span><span class="p">)</span> <span class="c1"># Deleted indexes</span> <span class="k">for</span> <span class="n">fields</span> <span class="ow">in</span> <span class="n">olds</span><span class="o">.</span><span class="n">difference</span><span class="p">(</span><span class="n">news</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">_delete_composed_index</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">fields</span><span class="p">,</span> <span class="p">{</span><span class="s1">'index'</span><span class="p">:</span> <span class="kc">True</span><span class="p">},</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_index</span><span class="p">)</span> <span class="c1"># Created indexes</span> <span class="k">for</span> <span class="n">field_names</span> <span class="ow">in</span> <span class="n">news</span><span class="o">.</span><span class="n">difference</span><span class="p">(</span><span class="n">olds</span><span class="p">):</span> <span class="n">fields</span> <span class="o">=</span> <span class="p">[</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">field</span><span class="p">)</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">field_names</span><span class="p">]</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">fields</span><span class="p">,</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">"_idx"</span><span class="p">))</span></div> <span class="k">def</span> <span class="nf">_delete_composed_index</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">fields</span><span class="p">,</span> <span class="n">constraint_kwargs</span><span class="p">,</span> <span class="n">sql</span><span class="p">):</span> <span class="n">columns</span> <span class="o">=</span> <span class="p">[</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">field</span><span class="p">)</span><span class="o">.</span><span class="n">column</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">fields</span><span class="p">]</span> <span class="n">constraint_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">columns</span><span class="p">,</span> <span class="o">**</span><span class="n">constraint_kwargs</span><span class="p">)</span> <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Found wrong number (</span><span class="si">%s</span><span class="s2">) of constraints for </span><span class="si">%s</span><span class="s2">(</span><span class="si">%s</span><span class="s2">)"</span> <span class="o">%</span> <span class="p">(</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">),</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="s2">", "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">columns</span><span class="p">),</span> <span class="p">))</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">constraint_names</span><span class="p">[</span><span class="mi">0</span><span class="p">]))</span> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.alter_db_table"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.alter_db_table">[docs]</a> <span class="k">def</span> <span class="nf">alter_db_table</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_db_table</span><span class="p">,</span> <span class="n">new_db_table</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Renames the table a model points to.</span> <span class="sd"> """</span> <span class="k">if</span> <span class="n">old_db_table</span> <span class="o">==</span> <span class="n">new_db_table</span><span class="p">:</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_rename_table</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"old_table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">old_db_table</span><span class="p">),</span> <span class="s2">"new_table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_db_table</span><span class="p">),</span> <span class="p">})</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.alter_db_tablespace"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.alter_db_tablespace">[docs]</a> <span class="k">def</span> <span class="nf">alter_db_tablespace</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_db_tablespace</span><span class="p">,</span> <span class="n">new_db_tablespace</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Moves a model's table between tablespaces</span> <span class="sd"> """</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_retablespace_table</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"old_tablespace"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">old_db_tablespace</span><span class="p">),</span> <span class="s2">"new_tablespace"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_db_tablespace</span><span class="p">),</span> <span class="p">})</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.add_field"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.add_field">[docs]</a> <span class="k">def</span> <span class="nf">add_field</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Creates a field on a model.</span> <span class="sd"> Usually involves adding a column, but may involve adding a</span> <span class="sd"> table instead (for M2M fields)</span> <span class="sd"> """</span> <span class="c1"># Special-case implicit M2M tables</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">many_to_many</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span><span class="p">:</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">create_model</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">)</span> <span class="c1"># Get the column's definition</span> <span class="n">definition</span><span class="p">,</span> <span class="n">params</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">column_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">,</span> <span class="n">include_default</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># It might not actually have a column behind it</span> <span class="k">if</span> <span class="n">definition</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span> <span class="k">return</span> <span class="c1"># Check constraints can go on the column SQL here</span> <span class="n">db_params</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="k">if</span> <span class="n">db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]:</span> <span class="n">definition</span> <span class="o">+=</span> <span class="s2">" CHECK (</span><span class="si">%s</span><span class="s2">)"</span> <span class="o">%</span> <span class="n">db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="c1"># Build the SQL and run it</span> <span class="n">sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"definition"</span><span class="p">:</span> <span class="n">definition</span><span class="p">,</span> <span class="p">}</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">params</span><span class="p">)</span> <span class="c1"># Drop the default if we need to</span> <span class="c1"># (Django usually does not use in-database defaults)</span> <span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">skip_default</span><span class="p">(</span><span class="n">field</span><span class="p">)</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">default</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span> <span class="n">sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"changes"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_no_default</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="p">}</span> <span class="p">}</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span> <span class="c1"># Add an index, if required</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">db_index</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">field</span><span class="o">.</span><span class="n">unique</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">field</span><span class="p">]))</span> <span class="c1"># Add any FK constraints later</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">supports_foreign_keys</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">db_constraint</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">deferred_sql</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_fk_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">,</span> <span class="s2">"_fk_</span><span class="si">%(to_table)s</span><span class="s2">_</span><span class="si">%(to_column)s</span><span class="s2">"</span><span class="p">))</span> <span class="c1"># Reset connection if required</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">connection_persists_old_columns</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">close</span><span class="p">()</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.remove_field"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.remove_field">[docs]</a> <span class="k">def</span> <span class="nf">remove_field</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Removes a field from a model. Usually involves deleting a column,</span> <span class="sd"> but for M2Ms may involve deleting a table.</span> <span class="sd"> """</span> <span class="c1"># Special-case implicit M2M tables</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">many_to_many</span> <span class="ow">and</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span><span class="p">:</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">delete_model</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">)</span> <span class="c1"># It might not actually have a column behind it</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)[</span><span class="s1">'type'</span><span class="p">]</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span> <span class="k">return</span> <span class="c1"># Drop any FK constraints, MySQL requires explicit deletion</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">rel</span><span class="p">:</span> <span class="n">fk_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">foreign_key</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">for</span> <span class="n">fk_name</span> <span class="ow">in</span> <span class="n">fk_names</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_fk</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">fk_name</span><span class="p">))</span> <span class="c1"># Delete the column</span> <span class="n">sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="p">}</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span> <span class="c1"># Reset connection if required</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">connection_persists_old_columns</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">close</span><span class="p">()</span></div> <div class="viewcode-block" id="BaseDatabaseSchemaEditor.alter_field"><a class="viewcode-back" href="../../../../../ref/schema-editor.html#django.db.backends.base.schema.BaseDatabaseSchemaEditor.alter_field">[docs]</a> <span class="k">def</span> <span class="nf">alter_field</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">strict</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Allows a field's type, uniqueness, nullability, default, column,</span> <span class="sd"> constraints etc. to be modified.</span> <span class="sd"> Requires a copy of the old field as well so we can only perform</span> <span class="sd"> changes that are required.</span> <span class="sd"> If strict is true, raises errors if the old column does not match old_field precisely.</span> <span class="sd"> """</span> <span class="c1"># Ensure this field is even column-based</span> <span class="n">old_db_params</span> <span class="o">=</span> <span class="n">old_field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="n">old_type</span> <span class="o">=</span> <span class="n">old_db_params</span><span class="p">[</span><span class="s1">'type'</span><span class="p">]</span> <span class="n">new_db_params</span> <span class="o">=</span> <span class="n">new_field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="n">new_type</span> <span class="o">=</span> <span class="n">new_db_params</span><span class="p">[</span><span class="s1">'type'</span><span class="p">]</span> <span class="k">if</span> <span class="p">((</span><span class="n">old_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">)</span> <span class="ow">or</span> <span class="p">(</span><span class="n">new_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">)):</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span> <span class="s2">"Cannot alter field </span><span class="si">%s</span><span class="s2"> into </span><span class="si">%s</span><span class="s2"> - they do not properly define "</span> <span class="s2">"db_type (are you using PostGIS 1.5 or badly-written custom "</span> <span class="s2">"fields?)"</span> <span class="o">%</span> <span class="p">(</span><span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">),</span> <span class="p">)</span> <span class="k">elif</span> <span class="n">old_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">new_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="p">(</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span> <span class="ow">and</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span><span class="p">):</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_alter_many_to_many</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">strict</span><span class="p">)</span> <span class="k">elif</span> <span class="n">old_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">new_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="p">(</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">auto_created</span><span class="p">):</span> <span class="c1"># Both sides have through models; this is a no-op.</span> <span class="k">return</span> <span class="k">elif</span> <span class="n">old_type</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">or</span> <span class="n">new_type</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span> <span class="s2">"Cannot alter field </span><span class="si">%s</span><span class="s2"> into </span><span class="si">%s</span><span class="s2"> - they are not compatible types "</span> <span class="s2">"(you cannot alter to or from M2M fields, or add or remove "</span> <span class="s2">"through= on M2M fields)"</span> <span class="o">%</span> <span class="p">(</span><span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">)</span> <span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">_alter_field</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">old_type</span><span class="p">,</span> <span class="n">new_type</span><span class="p">,</span> <span class="n">old_db_params</span><span class="p">,</span> <span class="n">new_db_params</span><span class="p">,</span> <span class="n">strict</span><span class="p">)</span></div> <span class="k">def</span> <span class="nf">_alter_field</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">old_type</span><span class="p">,</span> <span class="n">new_type</span><span class="p">,</span> <span class="n">old_db_params</span><span class="p">,</span> <span class="n">new_db_params</span><span class="p">,</span> <span class="n">strict</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span> <span class="sd">"""Actually perform a "physical" (non-ManyToMany) field update."""</span> <span class="c1"># Drop any FK constraints, we'll remake them later</span> <span class="n">fks_dropped</span> <span class="o">=</span> <span class="nb">set</span><span class="p">()</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">and</span> <span class="n">old_field</span><span class="o">.</span><span class="n">db_constraint</span><span class="p">:</span> <span class="n">fk_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">foreign_key</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">if</span> <span class="n">strict</span> <span class="ow">and</span> <span class="nb">len</span><span class="p">(</span><span class="n">fk_names</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Found wrong number (</span><span class="si">%s</span><span class="s2">) of foreign key constraints for </span><span class="si">%s</span><span class="s2">.</span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span> <span class="nb">len</span><span class="p">(</span><span class="n">fk_names</span><span class="p">),</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">,</span> <span class="p">))</span> <span class="k">for</span> <span class="n">fk_name</span> <span class="ow">in</span> <span class="n">fk_names</span><span class="p">:</span> <span class="n">fks_dropped</span><span class="o">.</span><span class="n">add</span><span class="p">((</span><span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">,))</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_fk</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">fk_name</span><span class="p">))</span> <span class="c1"># Has unique been removed?</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">and</span> <span class="p">(</span><span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">or</span> <span class="p">(</span><span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">primary_key</span><span class="p">)):</span> <span class="c1"># Find the unique constraint for this field</span> <span class="n">constraint_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">unique</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">if</span> <span class="n">strict</span> <span class="ow">and</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Found wrong number (</span><span class="si">%s</span><span class="s2">) of unique constraints for </span><span class="si">%s</span><span class="s2">.</span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">),</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">,</span> <span class="p">))</span> <span class="k">for</span> <span class="n">constraint_name</span> <span class="ow">in</span> <span class="n">constraint_names</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_unique</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">constraint_name</span><span class="p">))</span> <span class="c1"># Drop incoming FK constraints if we're a primary key and things are going</span> <span class="c1"># to change.</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">old_type</span> <span class="o">!=</span> <span class="n">new_type</span><span class="p">:</span> <span class="c1"># '_meta.related_field' also contains M2M reverse fields, these</span> <span class="c1"># will be filtered out</span> <span class="k">for</span> <span class="n">_old_rel</span><span class="p">,</span> <span class="n">new_rel</span> <span class="ow">in</span> <span class="n">_related_non_m2m_objects</span><span class="p">(</span><span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">):</span> <span class="n">rel_fk_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span> <span class="n">new_rel</span><span class="o">.</span><span class="n">related_model</span><span class="p">,</span> <span class="p">[</span><span class="n">new_rel</span><span class="o">.</span><span class="n">field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">foreign_key</span><span class="o">=</span><span class="kc">True</span> <span class="p">)</span> <span class="k">for</span> <span class="n">fk_name</span> <span class="ow">in</span> <span class="n">rel_fk_names</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_fk</span><span class="p">,</span> <span class="n">new_rel</span><span class="o">.</span><span class="n">related_model</span><span class="p">,</span> <span class="n">fk_name</span><span class="p">))</span> <span class="c1"># Removed an index? (no strict check, as multiple indexes are possible)</span> <span class="k">if</span> <span class="p">(</span><span class="n">old_field</span><span class="o">.</span><span class="n">db_index</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">db_index</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">and</span> <span class="ow">not</span> <span class="p">(</span><span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">and</span> <span class="n">old_field</span><span class="o">.</span><span class="n">unique</span><span class="p">)):</span> <span class="c1"># Find the index for this field</span> <span class="n">index_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">index</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">for</span> <span class="n">index_name</span> <span class="ow">in</span> <span class="n">index_names</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_index</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">index_name</span><span class="p">))</span> <span class="c1"># Change check constraints?</span> <span class="k">if</span> <span class="n">old_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="o">!=</span> <span class="n">new_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="ow">and</span> <span class="n">old_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]:</span> <span class="n">constraint_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">check</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">if</span> <span class="n">strict</span> <span class="ow">and</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Found wrong number (</span><span class="si">%s</span><span class="s2">) of check constraints for </span><span class="si">%s</span><span class="s2">.</span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">),</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">,</span> <span class="p">))</span> <span class="k">for</span> <span class="n">constraint_name</span> <span class="ow">in</span> <span class="n">constraint_names</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_check</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">constraint_name</span><span class="p">))</span> <span class="c1"># Have they renamed the column?</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">column</span> <span class="o">!=</span> <span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_rename_field_sql</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">new_type</span><span class="p">))</span> <span class="c1"># Next, start accumulating actions to do</span> <span class="n">actions</span> <span class="o">=</span> <span class="p">[]</span> <span class="n">null_actions</span> <span class="o">=</span> <span class="p">[]</span> <span class="n">post_actions</span> <span class="o">=</span> <span class="p">[]</span> <span class="c1"># Type change?</span> <span class="k">if</span> <span class="n">old_type</span> <span class="o">!=</span> <span class="n">new_type</span><span class="p">:</span> <span class="n">fragment</span><span class="p">,</span> <span class="n">other_actions</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_alter_column_type_sql</span><span class="p">(</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">new_type</span> <span class="p">)</span> <span class="n">actions</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">fragment</span><span class="p">)</span> <span class="n">post_actions</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">other_actions</span><span class="p">)</span> <span class="c1"># When changing a column NULL constraint to NOT NULL with a given</span> <span class="c1"># default value, we need to perform 4 steps:</span> <span class="c1"># 1. Add a default for new incoming writes</span> <span class="c1"># 2. Update existing NULL rows with new default</span> <span class="c1"># 3. Replace NULL constraint with NOT NULL</span> <span class="c1"># 4. Drop the default again.</span> <span class="c1"># Default change?</span> <span class="n">old_default</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">effective_default</span><span class="p">(</span><span class="n">old_field</span><span class="p">)</span> <span class="n">new_default</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">effective_default</span><span class="p">(</span><span class="n">new_field</span><span class="p">)</span> <span class="n">needs_database_default</span> <span class="o">=</span> <span class="p">(</span> <span class="n">old_default</span> <span class="o">!=</span> <span class="n">new_default</span> <span class="ow">and</span> <span class="n">new_default</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">skip_default</span><span class="p">(</span><span class="n">new_field</span><span class="p">)</span> <span class="p">)</span> <span class="k">if</span> <span class="n">needs_database_default</span><span class="p">:</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">requires_literal_defaults</span><span class="p">:</span> <span class="c1"># Some databases can't take defaults as a parameter (oracle)</span> <span class="c1"># If this is the case, the individual schema backend should</span> <span class="c1"># implement prepare_default</span> <span class="n">actions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_default</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"default"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">prepare_default</span><span class="p">(</span><span class="n">new_default</span><span class="p">),</span> <span class="p">},</span> <span class="p">[],</span> <span class="p">))</span> <span class="k">else</span><span class="p">:</span> <span class="n">actions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_default</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"default"</span><span class="p">:</span> <span class="s2">"</span><span class="si">%s</span><span class="s2">"</span><span class="p">,</span> <span class="p">},</span> <span class="p">[</span><span class="n">new_default</span><span class="p">],</span> <span class="p">))</span> <span class="c1"># Nullability change?</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">null</span> <span class="o">!=</span> <span class="n">new_field</span><span class="o">.</span><span class="n">null</span><span class="p">:</span> <span class="k">if</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">interprets_empty_strings_as_nulls</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span> <span class="ow">in</span> <span class="p">(</span><span class="s2">"CharField"</span><span class="p">,</span> <span class="s2">"TextField"</span><span class="p">)):</span> <span class="c1"># The field is nullable in the database anyway, leave it alone</span> <span class="k">pass</span> <span class="k">elif</span> <span class="n">new_field</span><span class="o">.</span><span class="n">null</span><span class="p">:</span> <span class="n">null_actions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_null</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"type"</span><span class="p">:</span> <span class="n">new_type</span><span class="p">,</span> <span class="p">},</span> <span class="p">[],</span> <span class="p">))</span> <span class="k">else</span><span class="p">:</span> <span class="n">null_actions</span><span class="o">.</span><span class="n">append</span><span class="p">((</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_not_null</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"type"</span><span class="p">:</span> <span class="n">new_type</span><span class="p">,</span> <span class="p">},</span> <span class="p">[],</span> <span class="p">))</span> <span class="c1"># Only if we have a default and there is a change from NULL to NOT NULL</span> <span class="n">four_way_default_alteration</span> <span class="o">=</span> <span class="p">(</span> <span class="n">new_field</span><span class="o">.</span><span class="n">has_default</span><span class="p">()</span> <span class="ow">and</span> <span class="p">(</span><span class="n">old_field</span><span class="o">.</span><span class="n">null</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">null</span><span class="p">)</span> <span class="p">)</span> <span class="k">if</span> <span class="n">actions</span> <span class="ow">or</span> <span class="n">null_actions</span><span class="p">:</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">four_way_default_alteration</span><span class="p">:</span> <span class="c1"># If we don't have to do a 4-way default alteration we can</span> <span class="c1"># directly run a (NOT) NULL alteration</span> <span class="n">actions</span> <span class="o">=</span> <span class="n">actions</span> <span class="o">+</span> <span class="n">null_actions</span> <span class="c1"># Combine actions together if we can (e.g. postgres)</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">supports_combined_alters</span> <span class="ow">and</span> <span class="n">actions</span><span class="p">:</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="o">=</span> <span class="nb">tuple</span><span class="p">(</span><span class="nb">zip</span><span class="p">(</span><span class="o">*</span><span class="n">actions</span><span class="p">))</span> <span class="n">actions</span> <span class="o">=</span> <span class="p">[(</span><span class="s2">", "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">sql</span><span class="p">),</span> <span class="nb">sum</span><span class="p">(</span><span class="n">params</span><span class="p">,</span> <span class="p">[]))]</span> <span class="c1"># Apply those actions</span> <span class="k">for</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="ow">in</span> <span class="n">actions</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"changes"</span><span class="p">:</span> <span class="n">sql</span><span class="p">,</span> <span class="p">},</span> <span class="n">params</span><span class="p">,</span> <span class="p">)</span> <span class="k">if</span> <span class="n">four_way_default_alteration</span><span class="p">:</span> <span class="c1"># Update existing rows with default value</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_update_with_default</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"default"</span><span class="p">:</span> <span class="s2">"</span><span class="si">%s</span><span class="s2">"</span><span class="p">,</span> <span class="p">},</span> <span class="p">[</span><span class="n">new_default</span><span class="p">],</span> <span class="p">)</span> <span class="c1"># Since we didn't run a NOT NULL change before we need to do it</span> <span class="c1"># now</span> <span class="k">for</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="ow">in</span> <span class="n">null_actions</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"changes"</span><span class="p">:</span> <span class="n">sql</span><span class="p">,</span> <span class="p">},</span> <span class="n">params</span><span class="p">,</span> <span class="p">)</span> <span class="k">if</span> <span class="n">post_actions</span><span class="p">:</span> <span class="k">for</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="ow">in</span> <span class="n">post_actions</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">params</span><span class="p">)</span> <span class="c1"># Added a unique?</span> <span class="k">if</span> <span class="p">(</span><span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">unique</span><span class="p">)</span> <span class="ow">or</span> <span class="p">(</span> <span class="n">old_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">unique</span> <span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_unique_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">]))</span> <span class="c1"># Added an index?</span> <span class="k">if</span> <span class="p">(</span><span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">db_index</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">db_index</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">new_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">and</span> <span class="ow">not</span> <span class="p">(</span><span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">unique</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">unique</span><span class="p">)):</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">new_field</span><span class="p">],</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">"_uniq"</span><span class="p">))</span> <span class="c1"># Type alteration on primary key? Then we need to alter the column</span> <span class="c1"># referring to us.</span> <span class="n">rels_to_update</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">old_type</span> <span class="o">!=</span> <span class="n">new_type</span><span class="p">:</span> <span class="n">rels_to_update</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">_related_non_m2m_objects</span><span class="p">(</span><span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">))</span> <span class="c1"># Changed to become primary key?</span> <span class="c1"># Note that we don't detect unsetting of a PK, as we assume another field</span> <span class="c1"># will always come along and replace it.</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">primary_key</span><span class="p">:</span> <span class="c1"># First, drop the old PK</span> <span class="n">constraint_names</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_constraint_names</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">primary_key</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="k">if</span> <span class="n">strict</span> <span class="ow">and</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">"Found wrong number (</span><span class="si">%s</span><span class="s2">) of PK constraints for </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span> <span class="nb">len</span><span class="p">(</span><span class="n">constraint_names</span><span class="p">),</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="p">))</span> <span class="k">for</span> <span class="n">constraint_name</span> <span class="ow">in</span> <span class="n">constraint_names</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">sql_delete_pk</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">constraint_name</span><span class="p">))</span> <span class="c1"># Make the new one</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_pk</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"name"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_name</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">"_pk"</span><span class="p">)),</span> <span class="s2">"columns"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="p">}</span> <span class="p">)</span> <span class="c1"># Update all referencing columns</span> <span class="n">rels_to_update</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">_related_non_m2m_objects</span><span class="p">(</span><span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">))</span> <span class="c1"># Handle our type alters on the other end of rels from the PK stuff above</span> <span class="k">for</span> <span class="n">old_rel</span><span class="p">,</span> <span class="n">new_rel</span> <span class="ow">in</span> <span class="n">rels_to_update</span><span class="p">:</span> <span class="n">rel_db_params</span> <span class="o">=</span> <span class="n">new_rel</span><span class="o">.</span><span class="n">field</span><span class="o">.</span><span class="n">db_parameters</span><span class="p">(</span><span class="n">connection</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="p">)</span> <span class="n">rel_type</span> <span class="o">=</span> <span class="n">rel_db_params</span><span class="p">[</span><span class="s1">'type'</span><span class="p">]</span> <span class="n">fragment</span><span class="p">,</span> <span class="n">other_actions</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_alter_column_type_sql</span><span class="p">(</span> <span class="n">new_rel</span><span class="o">.</span><span class="n">related_model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">old_rel</span><span class="o">.</span><span class="n">field</span><span class="p">,</span> <span class="n">new_rel</span><span class="o">.</span><span class="n">field</span><span class="p">,</span> <span class="n">rel_type</span> <span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_rel</span><span class="o">.</span><span class="n">related_model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"changes"</span><span class="p">:</span> <span class="n">fragment</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="p">},</span> <span class="n">fragment</span><span class="p">[</span><span class="mi">1</span><span class="p">],</span> <span class="p">)</span> <span class="k">for</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span> <span class="ow">in</span> <span class="n">other_actions</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span> <span class="n">params</span><span class="p">)</span> <span class="c1"># Does it have a foreign key?</span> <span class="k">if</span> <span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">and</span> <span class="p">(</span><span class="n">fks_dropped</span> <span class="ow">or</span> <span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span> <span class="ow">or</span> <span class="ow">not</span> <span class="n">old_field</span><span class="o">.</span><span class="n">db_constraint</span><span class="p">)</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">db_constraint</span><span class="p">):</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_fk_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="s2">"_fk_</span><span class="si">%(to_table)s</span><span class="s2">_</span><span class="si">%(to_column)s</span><span class="s2">"</span><span class="p">))</span> <span class="c1"># Rebuild FKs that pointed to us if we previously had to drop them</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">new_field</span><span class="o">.</span><span class="n">primary_key</span> <span class="ow">and</span> <span class="n">old_type</span> <span class="o">!=</span> <span class="n">new_type</span><span class="p">:</span> <span class="k">for</span> <span class="n">rel</span> <span class="ow">in</span> <span class="n">new_field</span><span class="o">.</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">related_objects</span><span class="p">:</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">rel</span><span class="o">.</span><span class="n">many_to_many</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_fk_sql</span><span class="p">(</span><span class="n">rel</span><span class="o">.</span><span class="n">related_model</span><span class="p">,</span> <span class="n">rel</span><span class="o">.</span><span class="n">field</span><span class="p">,</span> <span class="s2">"_fk"</span><span class="p">))</span> <span class="c1"># Does it have check constraints we need to add?</span> <span class="k">if</span> <span class="n">old_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="o">!=</span> <span class="n">new_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="ow">and</span> <span class="n">new_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]:</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_check</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"name"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_name</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">],</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">"_check"</span><span class="p">)),</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"check"</span><span class="p">:</span> <span class="n">new_db_params</span><span class="p">[</span><span class="s1">'check'</span><span class="p">],</span> <span class="p">}</span> <span class="p">)</span> <span class="c1"># Drop the default if we need to</span> <span class="c1"># (Django usually does not use in-database defaults)</span> <span class="k">if</span> <span class="n">needs_database_default</span><span class="p">:</span> <span class="n">sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"changes"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_no_default</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="p">}</span> <span class="p">}</span> <span class="bp">self</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span> <span class="c1"># Reset connection if required</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">connection_persists_old_columns</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">close</span><span class="p">()</span> <span class="k">def</span> <span class="nf">_alter_column_type_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">table</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">new_type</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Hook to specialize column type alteration for different backends,</span> <span class="sd"> for cases when a creation type is different to an alteration type</span> <span class="sd"> (e.g. SERIAL in PostgreSQL, PostGIS fields).</span> <span class="sd"> Should return two things; an SQL fragment of (sql, params) to insert</span> <span class="sd"> into an ALTER TABLE statement, and a list of extra (sql, params) tuples</span> <span class="sd"> to run once the field is altered.</span> <span class="sd"> """</span> <span class="k">return</span> <span class="p">(</span> <span class="p">(</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_alter_column_type</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"type"</span><span class="p">:</span> <span class="n">new_type</span><span class="p">,</span> <span class="p">},</span> <span class="p">[],</span> <span class="p">),</span> <span class="p">[],</span> <span class="p">)</span> <span class="k">def</span> <span class="nf">_alter_many_to_many</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">strict</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Alters M2Ms to repoint their to= endpoints.</span> <span class="sd"> """</span> <span class="c1"># Rename the through table</span> <span class="k">if</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span> <span class="o">!=</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">alter_db_table</span><span class="p">(</span><span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">,</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">)</span> <span class="c1"># Repoint the FK to the other side</span> <span class="bp">self</span><span class="o">.</span><span class="n">alter_field</span><span class="p">(</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">,</span> <span class="c1"># We need the field that points to the target model, so we can tell alter_field to change it -</span> <span class="c1"># this is m2m_reverse_field_name() (as opposed to m2m_field_name, which points to our model)</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">old_field</span><span class="o">.</span><span class="n">m2m_reverse_field_name</span><span class="p">()),</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">m2m_reverse_field_name</span><span class="p">()),</span> <span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">alter_field</span><span class="p">(</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="p">,</span> <span class="c1"># for self-referential models we need to alter field from the other end too</span> <span class="n">old_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">old_field</span><span class="o">.</span><span class="n">m2m_field_name</span><span class="p">()),</span> <span class="n">new_field</span><span class="o">.</span><span class="n">rel</span><span class="o">.</span><span class="n">through</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">m2m_field_name</span><span class="p">()),</span> <span class="p">)</span> <span class="k">def</span> <span class="nf">_create_index_name</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">column_names</span><span class="p">,</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">""</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Generates a unique name for an index/unique constraint.</span> <span class="sd"> """</span> <span class="c1"># If there is just one column in the index, use a default algorithm from Django</span> <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">column_names</span><span class="p">)</span> <span class="o">==</span> <span class="mi">1</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">suffix</span><span class="p">:</span> <span class="k">return</span> <span class="n">truncate_name</span><span class="p">(</span> <span class="s1">'</span><span class="si">%s</span><span class="s1">_</span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_digest</span><span class="p">(</span><span class="n">column_names</span><span class="p">[</span><span class="mi">0</span><span class="p">])),</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">max_name_length</span><span class="p">()</span> <span class="p">)</span> <span class="c1"># Else generate the name for the index using a different algorithm</span> <span class="n">table_name</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s1">'"'</span><span class="p">,</span> <span class="s1">''</span><span class="p">)</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s1">'.'</span><span class="p">,</span> <span class="s1">'_'</span><span class="p">)</span> <span class="n">index_unique_name</span> <span class="o">=</span> <span class="s1">'_</span><span class="si">%x</span><span class="s1">'</span> <span class="o">%</span> <span class="nb">abs</span><span class="p">(</span><span class="nb">hash</span><span class="p">((</span><span class="n">table_name</span><span class="p">,</span> <span class="s1">','</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">column_names</span><span class="p">))))</span> <span class="n">max_length</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">max_name_length</span><span class="p">()</span> <span class="ow">or</span> <span class="mi">200</span> <span class="c1"># If the index name is too long, truncate it</span> <span class="n">index_name</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'</span><span class="si">%s</span><span class="s1">_</span><span class="si">%s%s%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span> <span class="n">table_name</span><span class="p">,</span> <span class="n">column_names</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="n">index_unique_name</span><span class="p">,</span> <span class="n">suffix</span><span class="p">,</span> <span class="p">))</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s1">'"'</span><span class="p">,</span> <span class="s1">''</span><span class="p">)</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="s1">'.'</span><span class="p">,</span> <span class="s1">'_'</span><span class="p">)</span> <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">index_name</span><span class="p">)</span> <span class="o">></span> <span class="n">max_length</span><span class="p">:</span> <span class="n">part</span> <span class="o">=</span> <span class="p">(</span><span class="s1">'_</span><span class="si">%s%s%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">column_names</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="n">index_unique_name</span><span class="p">,</span> <span class="n">suffix</span><span class="p">))</span> <span class="n">index_name</span> <span class="o">=</span> <span class="s1">'</span><span class="si">%s%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">table_name</span><span class="p">[:(</span><span class="n">max_length</span> <span class="o">-</span> <span class="nb">len</span><span class="p">(</span><span class="n">part</span><span class="p">))],</span> <span class="n">part</span><span class="p">)</span> <span class="c1"># It shouldn't start with an underscore (Oracle hates this)</span> <span class="k">if</span> <span class="n">index_name</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">==</span> <span class="s2">"_"</span><span class="p">:</span> <span class="n">index_name</span> <span class="o">=</span> <span class="n">index_name</span><span class="p">[</span><span class="mi">1</span><span class="p">:]</span> <span class="c1"># If it's STILL too long, just hash it down</span> <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">index_name</span><span class="p">)</span> <span class="o">></span> <span class="n">max_length</span><span class="p">:</span> <span class="n">index_name</span> <span class="o">=</span> <span class="n">hashlib</span><span class="o">.</span><span class="n">md5</span><span class="p">(</span><span class="n">force_bytes</span><span class="p">(</span><span class="n">index_name</span><span class="p">))</span><span class="o">.</span><span class="n">hexdigest</span><span class="p">()[:</span><span class="n">max_length</span><span class="p">]</span> <span class="c1"># It can't start with a number on Oracle, so prepend D if we need to</span> <span class="k">if</span> <span class="n">index_name</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">isdigit</span><span class="p">():</span> <span class="n">index_name</span> <span class="o">=</span> <span class="s2">"D</span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">index_name</span><span class="p">[:</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="k">return</span> <span class="n">index_name</span> <span class="k">def</span> <span class="nf">_create_index_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">fields</span><span class="p">,</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">""</span><span class="p">,</span> <span class="n">sql</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Return the SQL statement to create the index for one or several fields.</span> <span class="sd"> `sql` can be specified if the syntax differs from the standard (GIS</span> <span class="sd"> indexes, ...).</span> <span class="sd"> """</span> <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">fields</span><span class="p">)</span> <span class="o">==</span> <span class="mi">1</span> <span class="ow">and</span> <span class="n">fields</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">db_tablespace</span><span class="p">:</span> <span class="n">tablespace_sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">tablespace_sql</span><span class="p">(</span><span class="n">fields</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">db_tablespace</span><span class="p">)</span> <span class="k">elif</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_tablespace</span><span class="p">:</span> <span class="n">tablespace_sql</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">tablespace_sql</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_tablespace</span><span class="p">)</span> <span class="k">else</span><span class="p">:</span> <span class="n">tablespace_sql</span> <span class="o">=</span> <span class="s2">""</span> <span class="k">if</span> <span class="n">tablespace_sql</span><span class="p">:</span> <span class="n">tablespace_sql</span> <span class="o">=</span> <span class="s2">" "</span> <span class="o">+</span> <span class="n">tablespace_sql</span> <span class="n">columns</span> <span class="o">=</span> <span class="p">[</span><span class="n">field</span><span class="o">.</span><span class="n">column</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">fields</span><span class="p">]</span> <span class="n">sql_create_index</span> <span class="o">=</span> <span class="n">sql</span> <span class="ow">or</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_index</span> <span class="k">return</span> <span class="n">sql_create_index</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"name"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_name</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">columns</span><span class="p">,</span> <span class="n">suffix</span><span class="o">=</span><span class="n">suffix</span><span class="p">)),</span> <span class="s2">"columns"</span><span class="p">:</span> <span class="s2">", "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">column</span><span class="p">)</span> <span class="k">for</span> <span class="n">column</span> <span class="ow">in</span> <span class="n">columns</span><span class="p">),</span> <span class="s2">"extra"</span><span class="p">:</span> <span class="n">tablespace_sql</span><span class="p">,</span> <span class="p">}</span> <span class="k">def</span> <span class="nf">_model_indexes_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Return all index SQL statements (field indexes, index_together) for the</span> <span class="sd"> specified model, as a list.</span> <span class="sd"> """</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">managed</span> <span class="ow">or</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">proxy</span> <span class="ow">or</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">swapped</span><span class="p">:</span> <span class="k">return</span> <span class="p">[]</span> <span class="n">output</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">local_fields</span><span class="p">:</span> <span class="k">if</span> <span class="n">field</span><span class="o">.</span><span class="n">db_index</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">field</span><span class="o">.</span><span class="n">unique</span><span class="p">:</span> <span class="n">output</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">field</span><span class="p">],</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">""</span><span class="p">))</span> <span class="k">for</span> <span class="n">field_names</span> <span class="ow">in</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">index_together</span><span class="p">:</span> <span class="n">fields</span> <span class="o">=</span> <span class="p">[</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">get_field</span><span class="p">(</span><span class="n">field</span><span class="p">)</span> <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">field_names</span><span class="p">]</span> <span class="n">output</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_sql</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">fields</span><span class="p">,</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">"_idx"</span><span class="p">))</span> <span class="k">return</span> <span class="n">output</span> <span class="k">def</span> <span class="nf">_rename_field_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">table</span><span class="p">,</span> <span class="n">old_field</span><span class="p">,</span> <span class="n">new_field</span><span class="p">,</span> <span class="n">new_type</span><span class="p">):</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_rename_column</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">table</span><span class="p">),</span> <span class="s2">"old_column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">old_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"new_column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">new_field</span><span class="o">.</span><span class="n">column</span><span class="p">),</span> <span class="s2">"type"</span><span class="p">:</span> <span class="n">new_type</span><span class="p">,</span> <span class="p">}</span> <span class="k">def</span> <span class="nf">_create_fk_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">field</span><span class="p">,</span> <span class="n">suffix</span><span class="p">):</span> <span class="n">from_table</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span> <span class="n">from_column</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">column</span> <span class="n">to_table</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">related_field</span><span class="o">.</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span> <span class="n">to_column</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">related_field</span><span class="o">.</span><span class="n">column</span> <span class="n">suffix</span> <span class="o">=</span> <span class="n">suffix</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"to_table"</span><span class="p">:</span> <span class="n">to_table</span><span class="p">,</span> <span class="s2">"to_column"</span><span class="p">:</span> <span class="n">to_column</span><span class="p">,</span> <span class="p">}</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_fk</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">from_table</span><span class="p">),</span> <span class="s2">"name"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_name</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="p">[</span><span class="n">from_column</span><span class="p">],</span> <span class="n">suffix</span><span class="o">=</span><span class="n">suffix</span><span class="p">)),</span> <span class="s2">"column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">from_column</span><span class="p">),</span> <span class="s2">"to_table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">to_table</span><span class="p">),</span> <span class="s2">"to_column"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">to_column</span><span class="p">),</span> <span class="p">}</span> <span class="k">def</span> <span class="nf">_create_unique_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">columns</span><span class="p">):</span> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql_create_unique</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"name"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_index_name</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">columns</span><span class="p">,</span> <span class="n">suffix</span><span class="o">=</span><span class="s2">"_uniq"</span><span class="p">)),</span> <span class="s2">"columns"</span><span class="p">:</span> <span class="s2">", "</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">column</span><span class="p">)</span> <span class="k">for</span> <span class="n">column</span> <span class="ow">in</span> <span class="n">columns</span><span class="p">),</span> <span class="p">}</span> <span class="k">def</span> <span class="nf">_delete_constraint_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">template</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">name</span><span class="p">):</span> <span class="k">return</span> <span class="n">template</span> <span class="o">%</span> <span class="p">{</span> <span class="s2">"table"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">),</span> <span class="s2">"name"</span><span class="p">:</span> <span class="bp">self</span><span class="o">.</span><span class="n">quote_name</span><span class="p">(</span><span class="n">name</span><span class="p">),</span> <span class="p">}</span> <span class="k">def</span> <span class="nf">_constraint_names</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">model</span><span class="p">,</span> <span class="n">column_names</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">unique</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">primary_key</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">index</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">foreign_key</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">check</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span> <span class="sd">"""</span> <span class="sd"> Returns all constraint names matching the columns and conditions</span> <span class="sd"> """</span> <span class="n">column_names</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">column_names</span><span class="p">)</span> <span class="k">if</span> <span class="n">column_names</span> <span class="k">else</span> <span class="kc">None</span> <span class="k">with</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">cursor</span><span class="p">()</span> <span class="k">as</span> <span class="n">cursor</span><span class="p">:</span> <span class="n">constraints</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">connection</span><span class="o">.</span><span class="n">introspection</span><span class="o">.</span><span class="n">get_constraints</span><span class="p">(</span><span class="n">cursor</span><span class="p">,</span> <span class="n">model</span><span class="o">.</span><span class="n">_meta</span><span class="o">.</span><span class="n">db_table</span><span class="p">)</span> <span class="n">result</span> <span class="o">=</span> <span class="p">[]</span> <span class="k">for</span> <span class="n">name</span><span class="p">,</span> <span class="n">infodict</span> <span class="ow">in</span> <span class="n">constraints</span><span class="o">.</span><span class="n">items</span><span class="p">():</span> <span class="k">if</span> <span class="n">column_names</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">or</span> <span class="n">column_names</span> <span class="o">==</span> <span class="n">infodict</span><span class="p">[</span><span class="s1">'columns'</span><span class="p">]:</span> <span class="k">if</span> <span class="n">unique</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">infodict</span><span class="p">[</span><span class="s1">'unique'</span><span class="p">]</span> <span class="o">!=</span> <span class="n">unique</span><span class="p">:</span> <span class="k">continue</span> <span class="k">if</span> <span class="n">primary_key</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">infodict</span><span class="p">[</span><span class="s1">'primary_key'</span><span class="p">]</span> <span class="o">!=</span> <span class="n">primary_key</span><span class="p">:</span> <span class="k">continue</span> <span class="k">if</span> <span class="n">index</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">infodict</span><span class="p">[</span><span class="s1">'index'</span><span class="p">]</span> <span class="o">!=</span> <span class="n">index</span><span class="p">:</span> <span class="k">continue</span> <span class="k">if</span> <span class="n">check</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">infodict</span><span class="p">[</span><span class="s1">'check'</span><span class="p">]</span> <span class="o">!=</span> <span class="n">check</span><span class="p">:</span> <span class="k">continue</span> <span class="k">if</span> <span class="n">foreign_key</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">infodict</span><span class="p">[</span><span class="s1">'foreign_key'</span><span class="p">]:</span> <span class="k">continue</span> <span class="n">result</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">name</span><span class="p">)</span> <span class="k">return</span> <span class="n">result</span></div> </pre></div> </div> </div> </div> <div class="yui-b" id="sidebar"> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3>Browse</h3> <ul> </ul> <h3>You are here:</h3> <ul> <li> <a href="../../../../../index.html">Django 1.8.19 documentation</a> <ul><li><a href="../../../../index.html">Module code</a> <ul><li><a href="../../../../django.html">django</a> <ul><li>django.db.backends.base.schema</li></ul> </li></ul></li></ul> </li> </ul> <div id="searchbox" style="display: none" role="search"> <h3>Quick search</h3> <form class="search" action="../../../../../search.html" method="get"> <div><input type="text" name="q" /></div> <div><input type="submit" value="Go" /></div> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> 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