<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>django.db.models.expressions — Django 1.8.19 documentation</title>
<link rel="stylesheet" href="../../../../_static/default.css" type="text/css" />
<link rel="stylesheet" href="../../../../_static/pygments.css" type="text/css" />
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: '../../../../',
VERSION: '1.8.19',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="../../../../_static/jquery.js"></script>
<script type="text/javascript" src="../../../../_static/underscore.js"></script>
<script type="text/javascript" src="../../../../_static/doctools.js"></script>
<link rel="index" title="Index" href="../../../../genindex.html" />
<link rel="search" title="Search" href="../../../../search.html" />
<link rel="top" title="Django 1.8.19 documentation" href="../../../../contents.html" />
<link rel="up" title="django" href="../../../django.html" />
<script type="text/javascript" src="../../../../templatebuiltins.js"></script>
<script type="text/javascript">
(function($) {
if (!django_template_builtins) {
// templatebuiltins.js missing, do nothing.
return;
}
$(document).ready(function() {
// Hyperlink Django template tags and filters
var base = "../../../../ref/templates/builtins.html";
if (base == "#") {
// Special case for builtins.html itself
base = "";
}
// Tags are keywords, class '.k'
$("div.highlight\\-html\\+django span.k").each(function(i, elem) {
var tagname = $(elem).text();
if ($.inArray(tagname, django_template_builtins.ttags) != -1) {
var fragment = tagname.replace(/_/, '-');
$(elem).html("<a href='" + base + "#" + fragment + "'>" + tagname + "</a>");
}
});
// Filters are functions, class '.nf'
$("div.highlight\\-html\\+django span.nf").each(function(i, elem) {
var filtername = $(elem).text();
if ($.inArray(filtername, django_template_builtins.tfilters) != -1) {
var fragment = filtername.replace(/_/, '-');
$(elem).html("<a href='" + base + "#" + fragment + "'>" + filtername + "</a>");
}
});
});
})(jQuery);
</script>
</head>
<body role="document">
<div class="document">
<div id="custom-doc" class="yui-t6">
<div id="hd">
<h1><a href="../../../../index.html">Django 1.8.19 documentation</a></h1>
<div id="global-nav">
<a title="Home page" href="../../../../index.html">Home</a> |
<a title="Table of contents" href="../../../../contents.html">Table of contents</a> |
<a title="Global index" href="../../../../genindex.html">Index</a> |
<a title="Module index" href="../../../../py-modindex.html">Modules</a>
</div>
<div class="nav">
<a href="../../../index.html" title="Module code" accesskey="U">up</a></div>
</div>
<div id="bd">
<div id="yui-main">
<div class="yui-b">
<div class="yui-g" id="_modules-django-db-models-expressions">
<h1>Source code for django.db.models.expressions</h1><div class="highlight"><pre>
<span></span><span class="kn">import</span> <span class="nn">copy</span>
<span class="kn">import</span> <span class="nn">datetime</span>
<span class="kn">from</span> <span class="nn">django.conf</span> <span class="k">import</span> <span class="n">settings</span>
<span class="kn">from</span> <span class="nn">django.core.exceptions</span> <span class="k">import</span> <span class="n">FieldError</span>
<span class="kn">from</span> <span class="nn">django.db.backends</span> <span class="k">import</span> <span class="n">utils</span> <span class="k">as</span> <span class="n">backend_utils</span>
<span class="kn">from</span> <span class="nn">django.db.models</span> <span class="k">import</span> <span class="n">fields</span>
<span class="kn">from</span> <span class="nn">django.db.models.constants</span> <span class="k">import</span> <span class="n">LOOKUP_SEP</span>
<span class="kn">from</span> <span class="nn">django.db.models.query_utils</span> <span class="k">import</span> <span class="n">Q</span><span class="p">,</span> <span class="n">refs_aggregate</span>
<span class="kn">from</span> <span class="nn">django.utils</span> <span class="k">import</span> <span class="n">six</span><span class="p">,</span> <span class="n">timezone</span>
<span class="kn">from</span> <span class="nn">django.utils.functional</span> <span class="k">import</span> <span class="n">cached_property</span>
<span class="k">class</span> <span class="nc">Combinable</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Provides the ability to combine one or two objects with</span>
<span class="sd"> some connector. For example F('foo') + F('bar').</span>
<span class="sd"> """</span>
<span class="c1"># Arithmetic connectors</span>
<span class="n">ADD</span> <span class="o">=</span> <span class="s1">'+'</span>
<span class="n">SUB</span> <span class="o">=</span> <span class="s1">'-'</span>
<span class="n">MUL</span> <span class="o">=</span> <span class="s1">'*'</span>
<span class="n">DIV</span> <span class="o">=</span> <span class="s1">'/'</span>
<span class="n">POW</span> <span class="o">=</span> <span class="s1">'^'</span>
<span class="c1"># The following is a quoted % operator - it is quoted because it can be</span>
<span class="c1"># used in strings that also have parameter substitution.</span>
<span class="n">MOD</span> <span class="o">=</span> <span class="s1">'</span><span class="si">%%</span><span class="s1">'</span>
<span class="c1"># Bitwise operators - note that these are generated by .bitand()</span>
<span class="c1"># and .bitor(), the '&' and '|' are reserved for boolean operator</span>
<span class="c1"># usage.</span>
<span class="n">BITAND</span> <span class="o">=</span> <span class="s1">'&'</span>
<span class="n">BITOR</span> <span class="o">=</span> <span class="s1">'|'</span>
<span class="k">def</span> <span class="nf">_combine</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">,</span> <span class="n">connector</span><span class="p">,</span> <span class="nb">reversed</span><span class="p">,</span> <span class="n">node</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="s1">'resolve_expression'</span><span class="p">):</span>
<span class="c1"># everything must be resolvable to an expression</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="n">datetime</span><span class="o">.</span><span class="n">timedelta</span><span class="p">):</span>
<span class="n">other</span> <span class="o">=</span> <span class="n">DurationValue</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="n">output_field</span><span class="o">=</span><span class="n">fields</span><span class="o">.</span><span class="n">DurationField</span><span class="p">())</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">other</span> <span class="o">=</span> <span class="n">Value</span><span class="p">(</span><span class="n">other</span><span class="p">)</span>
<span class="k">if</span> <span class="nb">reversed</span><span class="p">:</span>
<span class="k">return</span> <span class="n">CombinedExpression</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="n">connector</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span>
<span class="k">return</span> <span class="n">CombinedExpression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">connector</span><span class="p">,</span> <span class="n">other</span><span class="p">)</span>
<span class="c1">#############</span>
<span class="c1"># OPERATORS #</span>
<span class="c1">#############</span>
<span class="k">def</span> <span class="nf">__add__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">ADD</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__sub__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">SUB</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__mul__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">MUL</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__truediv__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">DIV</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__div__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span> <span class="c1"># Python 2 compatibility</span>
<span class="k">return</span> <span class="nb">type</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__truediv__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__mod__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">MOD</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__pow__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">POW</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__and__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">(</span>
<span class="s2">"Use .bitand() and .bitor() for bitwise logical operations."</span>
<span class="p">)</span>
<span class="k">def</span> <span class="nf">bitand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">BITAND</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__or__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">(</span>
<span class="s2">"Use .bitand() and .bitor() for bitwise logical operations."</span>
<span class="p">)</span>
<span class="k">def</span> <span class="nf">bitor</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">BITOR</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__radd__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">ADD</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rsub__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">SUB</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rmul__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">MUL</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rtruediv__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">DIV</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rdiv__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span> <span class="c1"># Python 2 compatibility</span>
<span class="k">return</span> <span class="nb">type</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__rtruediv__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rmod__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">MOD</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rpow__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_combine</span><span class="p">(</span><span class="n">other</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">POW</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__rand__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">(</span>
<span class="s2">"Use .bitand() and .bitor() for bitwise logical operations."</span>
<span class="p">)</span>
<span class="k">def</span> <span class="nf">__ror__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">(</span>
<span class="s2">"Use .bitand() and .bitor() for bitwise logical operations."</span>
<span class="p">)</span>
<span class="k">class</span> <span class="nc">BaseExpression</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Base class for all query expressions.</span>
<span class="sd"> """</span>
<span class="c1"># aggregate specific fields</span>
<span class="n">is_summary</span> <span class="o">=</span> <span class="kc">False</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">output_field</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span> <span class="o">=</span> <span class="n">output_field</span>
<span class="k">def</span> <span class="nf">get_db_converters</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="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">convert_value</span><span class="p">]</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="o">.</span><span class="n">get_db_converters</span><span class="p">(</span><span class="n">connection</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="k">assert</span> <span class="nb">len</span><span class="p">(</span><span class="n">exprs</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span>
<span class="k">def</span> <span class="nf">_parse_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">expressions</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span>
<span class="n">arg</span> <span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="s1">'resolve_expression'</span><span class="p">)</span> <span class="k">else</span> <span class="p">(</span>
<span class="n">F</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span> <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">arg</span><span class="p">,</span> <span class="n">six</span><span class="o">.</span><span class="n">string_types</span><span class="p">)</span> <span class="k">else</span> <span class="n">Value</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span>
<span class="p">)</span> <span class="k">for</span> <span class="n">arg</span> <span class="ow">in</span> <span class="n">expressions</span>
<span class="p">]</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Responsible for returning a (sql, [params]) tuple to be included</span>
<span class="sd"> in the current query.</span>
<span class="sd"> Different backends can provide their own implementation, by</span>
<span class="sd"> providing an `as_{vendor}` method and patching the Expression:</span>
<span class="sd"> ```</span>
<span class="sd"> def override_as_sql(self, compiler, connection):</span>
<span class="sd"> # custom logic</span>
<span class="sd"> return super(Expression, self).as_sql(compiler, connection)</span>
<span class="sd"> setattr(Expression, 'as_' + connection.vendor, override_as_sql)</span>
<span class="sd"> ```</span>
<span class="sd"> Arguments:</span>
<span class="sd"> * compiler: the query compiler responsible for generating the query.</span>
<span class="sd"> Must have a compile method, returning a (sql, [params]) tuple.</span>
<span class="sd"> Calling compiler(value) will return a quoted `value`.</span>
<span class="sd"> * connection: the database connection used for the current query.</span>
<span class="sd"> Returns: (sql, params)</span>
<span class="sd"> Where `sql` is a string containing ordered sql parameters to be</span>
<span class="sd"> replaced with the elements of the list `params`.</span>
<span class="sd"> """</span>
<span class="k">raise</span> <span class="ne">NotImplementedError</span><span class="p">(</span><span class="s2">"Subclasses must implement as_sql()"</span><span class="p">)</span>
<span class="nd">@cached_property</span>
<span class="k">def</span> <span class="nf">contains_aggregate</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">for</span> <span class="n">expr</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">():</span>
<span class="k">if</span> <span class="n">expr</span> <span class="ow">and</span> <span class="n">expr</span><span class="o">.</span><span class="n">contains_aggregate</span><span class="p">:</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">return</span> <span class="kc">False</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Provides the chance to do any preprocessing or validation before being</span>
<span class="sd"> added to the query.</span>
<span class="sd"> Arguments:</span>
<span class="sd"> * query: the backend query implementation</span>
<span class="sd"> * allow_joins: boolean allowing or denying use of joins</span>
<span class="sd"> in this query</span>
<span class="sd"> * reuse: a set of reusable joins for multijoins</span>
<span class="sd"> * summarize: a terminal aggregate clause</span>
<span class="sd"> * for_save: whether this expression about to be used in a save or update</span>
<span class="sd"> Returns: an Expression to be added to the query.</span>
<span class="sd"> """</span>
<span class="n">c</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">c</span><span class="o">.</span><span class="n">is_summary</span> <span class="o">=</span> <span class="n">summarize</span>
<span class="n">c</span><span class="o">.</span><span class="n">set_source_expressions</span><span class="p">([</span>
<span class="n">expr</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">)</span>
<span class="k">for</span> <span class="n">expr</span> <span class="ow">in</span> <span class="n">c</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">()</span>
<span class="p">])</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">_prepare</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Hook used by Field.get_prep_lookup() to do custom preparation.</span>
<span class="sd"> """</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="nd">@property</span>
<span class="k">def</span> <span class="nf">field</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span>
<span class="nd">@cached_property</span>
<span class="k">def</span> <span class="nf">output_field</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Returns the output type of this expressions.</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field_or_none</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">raise</span> <span class="n">FieldError</span><span class="p">(</span><span class="s2">"Cannot resolve expression type, unknown output_field"</span><span class="p">)</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field_or_none</span>
<span class="nd">@cached_property</span>
<span class="k">def</span> <span class="nf">_output_field_or_none</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Returns the output field of this expression, or None if no output type</span>
<span class="sd"> can be resolved. Note that the 'output_field' property will raise</span>
<span class="sd"> FieldError if no type can be resolved, but this attribute allows for</span>
<span class="sd"> None values.</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_resolve_output_field</span><span class="p">()</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span>
<span class="k">def</span> <span class="nf">_resolve_output_field</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Attempts to infer the output type of the expression. If the output</span>
<span class="sd"> fields of all source fields match then we can simply infer the same</span>
<span class="sd"> type here. This isn't always correct, but it makes sense most of the</span>
<span class="sd"> time.</span>
<span class="sd"> Consider the difference between `2 + 2` and `2 / 3`. Inferring</span>
<span class="sd"> the type here is a convenience for the common case. The user should</span>
<span class="sd"> supply their own output_field with more complex computations.</span>
<span class="sd"> If a source does not have an `_output_field` then we exclude it from</span>
<span class="sd"> this check. If all sources are `None`, then an error will be thrown</span>
<span class="sd"> higher up the stack in the `output_field` property.</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">sources</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_fields</span><span class="p">()</span>
<span class="n">num_sources</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">sources</span><span class="p">)</span>
<span class="k">if</span> <span class="n">num_sources</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">for</span> <span class="n">source</span> <span class="ow">in</span> <span class="n">sources</span><span class="p">:</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span> <span class="o">=</span> <span class="n">source</span>
<span class="k">if</span> <span class="n">source</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="nb">isinstance</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_output_field</span><span class="p">,</span> <span class="n">source</span><span class="o">.</span><span class="n">__class__</span><span class="p">):</span>
<span class="k">raise</span> <span class="n">FieldError</span><span class="p">(</span>
<span class="s2">"Expression contains mixed types. You must set output_field"</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">convert_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="n">expression</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Expressions provide their own converters because users have the option</span>
<span class="sd"> of manually specifying the output_field which may be a different type</span>
<span class="sd"> from the one the database returns.</span>
<span class="sd"> """</span>
<span class="n">field</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span>
<span class="n">internal_type</span> <span class="o">=</span> <span class="n">field</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span>
<span class="k">if</span> <span class="n">value</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">return</span> <span class="n">value</span>
<span class="k">elif</span> <span class="n">internal_type</span> <span class="o">==</span> <span class="s1">'FloatField'</span><span class="p">:</span>
<span class="k">return</span> <span class="nb">float</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
<span class="k">elif</span> <span class="n">internal_type</span><span class="o">.</span><span class="n">endswith</span><span class="p">(</span><span class="s1">'IntegerField'</span><span class="p">):</span>
<span class="k">return</span> <span class="nb">int</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
<span class="k">elif</span> <span class="n">internal_type</span> <span class="o">==</span> <span class="s1">'DecimalField'</span><span class="p">:</span>
<span class="k">return</span> <span class="n">backend_utils</span><span class="o">.</span><span class="n">typecast_decimal</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
<span class="k">return</span> <span class="n">value</span>
<span class="k">def</span> <span class="nf">get_lookup</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">lookup</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="o">.</span><span class="n">get_lookup</span><span class="p">(</span><span class="n">lookup</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_transform</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">output_field</span><span class="o">.</span><span class="n">get_transform</span><span class="p">(</span><span class="n">name</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">relabeled_clone</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">change_map</span><span class="p">):</span>
<span class="n">clone</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">clone</span><span class="o">.</span><span class="n">set_source_expressions</span><span class="p">(</span>
<span class="p">[</span><span class="n">e</span><span class="o">.</span><span class="n">relabeled_clone</span><span class="p">(</span><span class="n">change_map</span><span class="p">)</span> <span class="k">for</span> <span class="n">e</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">()])</span>
<span class="k">return</span> <span class="n">clone</span>
<span class="k">def</span> <span class="nf">copy</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="n">copy</span><span class="o">.</span><span class="n">copy</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">c</span><span class="o">.</span><span class="n">copied</span> <span class="o">=</span> <span class="kc">True</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">refs_aggregate</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">existing_aggregates</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Does this expression contain a reference to some of the</span>
<span class="sd"> existing aggregates? If so, returns the aggregate and also</span>
<span class="sd"> the lookup parts that *weren't* found. So, if</span>
<span class="sd"> existing_aggregates = {'max_id': Max('id')}</span>
<span class="sd"> self.name = 'max_id'</span>
<span class="sd"> queryset.filter(max_id__range=[10,100])</span>
<span class="sd"> then this method will return Max('id') and those parts of the</span>
<span class="sd"> name that weren't found. In this case `max_id` is found and the range</span>
<span class="sd"> portion is returned as ('range',).</span>
<span class="sd"> """</span>
<span class="k">for</span> <span class="n">node</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">():</span>
<span class="n">agg</span><span class="p">,</span> <span class="n">lookup</span> <span class="o">=</span> <span class="n">node</span><span class="o">.</span><span class="n">refs_aggregate</span><span class="p">(</span><span class="n">existing_aggregates</span><span class="p">)</span>
<span class="k">if</span> <span class="n">agg</span><span class="p">:</span>
<span class="k">return</span> <span class="n">agg</span><span class="p">,</span> <span class="n">lookup</span>
<span class="k">return</span> <span class="kc">False</span><span class="p">,</span> <span class="p">()</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">contains_aggregate</span><span class="p">:</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="p">]</span>
<span class="n">cols</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">source</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">():</span>
<span class="n">cols</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">source</span><span class="o">.</span><span class="n">get_group_by_cols</span><span class="p">())</span>
<span class="k">return</span> <span class="n">cols</span>
<span class="k">def</span> <span class="nf">get_source_fields</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Returns the underlying field types used by this</span>
<span class="sd"> aggregate.</span>
<span class="sd"> """</span>
<span class="k">return</span> <span class="p">[</span><span class="n">e</span><span class="o">.</span><span class="n">_output_field_or_none</span> <span class="k">for</span> <span class="n">e</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">()]</span>
<span class="k">def</span> <span class="nf">asc</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="n">OrderBy</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">desc</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="n">OrderBy</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">descending</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">reverse_ordering</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">def</span> <span class="nf">flatten</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Recursively yield this expression and all subexpressions, in</span>
<span class="sd"> depth-first order.</span>
<span class="sd"> """</span>
<span class="k">yield</span> <span class="bp">self</span>
<span class="k">for</span> <span class="n">expr</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">():</span>
<span class="k">if</span> <span class="n">expr</span><span class="p">:</span>
<span class="k">for</span> <span class="n">inner_expr</span> <span class="ow">in</span> <span class="n">expr</span><span class="o">.</span><span class="n">flatten</span><span class="p">():</span>
<span class="k">yield</span> <span class="n">inner_expr</span>
<div class="viewcode-block" id="Expression"><a class="viewcode-back" href="../../../../ref/models/expressions.html#django.db.models.expressions.Expression">[docs]</a><span class="k">class</span> <span class="nc">Expression</span><span class="p">(</span><span class="n">BaseExpression</span><span class="p">,</span> <span class="n">Combinable</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> An expression that can be combined with other expressions.</span>
<span class="sd"> """</span>
<span class="k">pass</span></div>
<span class="k">class</span> <span class="nc">CombinedExpression</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</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">lhs</span><span class="p">,</span> <span class="n">connector</span><span class="p">,</span> <span class="n">rhs</span><span class="p">,</span> <span class="n">output_field</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">CombinedExpression</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">output_field</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">connector</span> <span class="o">=</span> <span class="n">connector</span>
<span class="bp">self</span><span class="o">.</span><span class="n">lhs</span> <span class="o">=</span> <span class="n">lhs</span>
<span class="bp">self</span><span class="o">.</span><span class="n">rhs</span> <span class="o">=</span> <span class="n">rhs</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"<</span><span class="si">{}</span><span class="s2">: </span><span class="si">{}</span><span class="s2">>"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__str__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2"> </span><span class="si">{}</span><span class="s2"> </span><span class="si">{}</span><span class="s2">"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">connector</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">rhs</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">rhs</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">rhs</span> <span class="o">=</span> <span class="n">exprs</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">lhs_output</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="o">.</span><span class="n">output_field</span>
<span class="k">except</span> <span class="n">FieldError</span><span class="p">:</span>
<span class="n">lhs_output</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">rhs_output</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">rhs</span><span class="o">.</span><span class="n">output_field</span>
<span class="k">except</span> <span class="n">FieldError</span><span class="p">:</span>
<span class="n">rhs_output</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">if</span> <span class="p">(</span><span class="ow">not</span> <span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">has_native_duration_field</span> <span class="ow">and</span>
<span class="p">((</span><span class="n">lhs_output</span> <span class="ow">and</span> <span class="n">lhs_output</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span> <span class="o">==</span> <span class="s1">'DurationField'</span><span class="p">)</span>
<span class="ow">or</span> <span class="p">(</span><span class="n">rhs_output</span> <span class="ow">and</span> <span class="n">rhs_output</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span> <span class="o">==</span> <span class="s1">'DurationField'</span><span class="p">))):</span>
<span class="k">return</span> <span class="n">DurationExpression</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">connector</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">rhs</span><span class="p">)</span><span class="o">.</span><span class="n">as_sql</span><span class="p">(</span><span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="n">expressions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">expression_params</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="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="p">)</span>
<span class="n">expressions</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span>
<span class="n">expression_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">params</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="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">rhs</span><span class="p">)</span>
<span class="n">expressions</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span>
<span class="n">expression_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
<span class="c1"># order of precedence</span>
<span class="n">expression_wrapper</span> <span class="o">=</span> <span class="s1">'(</span><span class="si">%s</span><span class="s1">)'</span>
<span class="n">sql</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">combine_expression</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">connector</span><span class="p">,</span> <span class="n">expressions</span><span class="p">)</span>
<span class="k">return</span> <span class="n">expression_wrapper</span> <span class="o">%</span> <span class="n">sql</span><span class="p">,</span> <span class="n">expression_params</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">c</span><span class="o">.</span><span class="n">is_summary</span> <span class="o">=</span> <span class="n">summarize</span>
<span class="n">c</span><span class="o">.</span><span class="n">lhs</span> <span class="o">=</span> <span class="n">c</span><span class="o">.</span><span class="n">lhs</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="n">c</span><span class="o">.</span><span class="n">rhs</span> <span class="o">=</span> <span class="n">c</span><span class="o">.</span><span class="n">rhs</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">class</span> <span class="nc">DurationExpression</span><span class="p">(</span><span class="n">CombinedExpression</span><span class="p">):</span>
<span class="k">def</span> <span class="nf">compile</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">side</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">side</span><span class="p">,</span> <span class="n">DurationValue</span><span class="p">):</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">output</span> <span class="o">=</span> <span class="n">side</span><span class="o">.</span><span class="n">output_field</span>
<span class="k">except</span> <span class="n">FieldError</span><span class="p">:</span>
<span class="k">pass</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">if</span> <span class="n">output</span><span class="o">.</span><span class="n">get_internal_type</span><span class="p">()</span> <span class="o">==</span> <span class="s1">'DurationField'</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="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="n">side</span><span class="p">)</span>
<span class="k">return</span> <span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">format_for_duration_arithmetic</span><span class="p">(</span><span class="n">sql</span><span class="p">),</span> <span class="n">params</span>
<span class="k">return</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="n">side</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">expressions</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">expression_params</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="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lhs</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="n">expressions</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span>
<span class="n">expression_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">params</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="bp">self</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">rhs</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="n">expressions</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">sql</span><span class="p">)</span>
<span class="n">expression_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
<span class="c1"># order of precedence</span>
<span class="n">expression_wrapper</span> <span class="o">=</span> <span class="s1">'(</span><span class="si">%s</span><span class="s1">)'</span>
<span class="n">sql</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">combine_duration_expression</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">connector</span><span class="p">,</span> <span class="n">expressions</span><span class="p">)</span>
<span class="k">return</span> <span class="n">expression_wrapper</span> <span class="o">%</span> <span class="n">sql</span><span class="p">,</span> <span class="n">expression_params</span>
<div class="viewcode-block" id="F"><a class="viewcode-back" href="../../../../ref/models/expressions.html#django.db.models.expressions.F">[docs]</a><span class="k">class</span> <span class="nc">F</span><span class="p">(</span><span class="n">Combinable</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> An object capable of resolving references to existing query objects.</span>
<span class="sd"> """</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">name</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Arguments:</span>
<span class="sd"> * name: the name of the field this expression references</span>
<span class="sd"> """</span>
<span class="bp">self</span><span class="o">.</span><span class="n">name</span> <span class="o">=</span> <span class="n">name</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">name</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="k">return</span> <span class="n">query</span><span class="o">.</span><span class="n">resolve_ref</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">name</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">refs_aggregate</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">existing_aggregates</span><span class="p">):</span>
<span class="k">return</span> <span class="n">refs_aggregate</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">name</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="n">LOOKUP_SEP</span><span class="p">),</span> <span class="n">existing_aggregates</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">asc</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="n">OrderBy</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">desc</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="n">OrderBy</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">descending</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span></div>
<div class="viewcode-block" id="Func"><a class="viewcode-back" href="../../../../ref/models/expressions.html#django.db.models.expressions.Func">[docs]</a><span class="k">class</span> <span class="nc">Func</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> A SQL function call.</span>
<span class="sd"> """</span>
<span class="n">function</span> <span class="o">=</span> <span class="kc">None</span>
<span class="n">template</span> <span class="o">=</span> <span class="s1">'</span><span class="si">%(function)s</span><span class="s1">(</span><span class="si">%(expressions)s</span><span class="s1">)'</span>
<span class="n">arg_joiner</span> <span class="o">=</span> <span class="s1">', '</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="o">*</span><span class="n">expressions</span><span class="p">,</span> <span class="o">**</span><span class="n">extra</span><span class="p">):</span>
<span class="n">output_field</span> <span class="o">=</span> <span class="n">extra</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'output_field'</span><span class="p">,</span> <span class="kc">None</span><span class="p">)</span>
<span class="nb">super</span><span class="p">(</span><span class="n">Func</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">output_field</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">source_expressions</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parse_expressions</span><span class="p">(</span><span class="o">*</span><span class="n">expressions</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">extra</span> <span class="o">=</span> <span class="n">extra</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">args</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">arg_joiner</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="nb">str</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span> <span class="k">for</span> <span class="n">arg</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">source_expressions</span><span class="p">)</span>
<span class="n">extra</span> <span class="o">=</span> <span class="s1">', '</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="nb">str</span><span class="p">(</span><span class="n">key</span><span class="p">)</span> <span class="o">+</span> <span class="s1">'='</span> <span class="o">+</span> <span class="nb">str</span><span class="p">(</span><span class="n">val</span><span class="p">)</span> <span class="k">for</span> <span class="n">key</span><span class="p">,</span> <span class="n">val</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="o">.</span><span class="n">items</span><span class="p">())</span>
<span class="k">if</span> <span class="n">extra</span><span class="p">:</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="n">args</span><span class="p">,</span> <span class="n">extra</span><span class="p">)</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="n">args</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">source_expressions</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">source_expressions</span> <span class="o">=</span> <span class="n">exprs</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">c</span><span class="o">.</span><span class="n">is_summary</span> <span class="o">=</span> <span class="n">summarize</span>
<span class="k">for</span> <span class="n">pos</span><span class="p">,</span> <span class="n">arg</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">c</span><span class="o">.</span><span class="n">source_expressions</span><span class="p">):</span>
<span class="n">c</span><span class="o">.</span><span class="n">source_expressions</span><span class="p">[</span><span class="n">pos</span><span class="p">]</span> <span class="o">=</span> <span class="n">arg</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">function</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">template</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">sql_parts</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">arg</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">source_expressions</span><span class="p">:</span>
<span class="n">arg_sql</span><span class="p">,</span> <span class="n">arg_params</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="n">arg</span><span class="p">)</span>
<span class="n">sql_parts</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">arg_sql</span><span class="p">)</span>
<span class="n">params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">arg_params</span><span class="p">)</span>
<span class="k">if</span> <span class="n">function</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="p">[</span><span class="s1">'function'</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">'function'</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">function</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">extra</span><span class="p">[</span><span class="s1">'function'</span><span class="p">]</span> <span class="o">=</span> <span class="n">function</span>
<span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="p">[</span><span class="s1">'expressions'</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="p">[</span><span class="s1">'field'</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">arg_joiner</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">sql_parts</span><span class="p">)</span>
<span class="n">template</span> <span class="o">=</span> <span class="n">template</span> <span class="ow">or</span> <span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">'template'</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">template</span><span class="p">)</span>
<span class="k">return</span> <span class="n">template</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="p">,</span> <span class="n">params</span>
<span class="k">def</span> <span class="nf">copy</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">copy</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">Func</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">copy</span><span class="o">.</span><span class="n">source_expressions</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">source_expressions</span><span class="p">[:]</span>
<span class="n">copy</span><span class="o">.</span><span class="n">extra</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">extra</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="k">return</span> <span class="n">copy</span></div>
<div class="viewcode-block" id="Value"><a class="viewcode-back" href="../../../../ref/models/expressions.html#django.db.models.expressions.Value">[docs]</a><span class="k">class</span> <span class="nc">Value</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Represents a wrapped value as a node within an expression</span>
<span class="sd"> """</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">value</span><span class="p">,</span> <span class="n">output_field</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Arguments:</span>
<span class="sd"> * value: the value this expression represents. The value will be</span>
<span class="sd"> added into the sql parameter list and properly quoted.</span>
<span class="sd"> * output_field: an instance of the model field type that this</span>
<span class="sd"> expression will return, such as IntegerField() or CharField().</span>
<span class="sd"> """</span>
<span class="nb">super</span><span class="p">(</span><span class="n">Value</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">output_field</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">value</span> <span class="o">=</span> <span class="n">value</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">value</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">val</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">value</span>
<span class="c1"># check _output_field to avoid triggering an exception</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field</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">for_save</span><span class="p">:</span>
<span class="n">val</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="o">.</span><span class="n">get_db_prep_save</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="n">connection</span><span class="o">=</span><span class="n">connection</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">val</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="o">.</span><span class="n">get_db_prep_value</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="n">connection</span><span class="o">=</span><span class="n">connection</span><span class="p">)</span>
<span class="k">if</span> <span class="n">val</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="c1"># cx_Oracle does not always convert None to the appropriate</span>
<span class="c1"># NULL type (like in case expressions using numbers), so we</span>
<span class="c1"># use a literal SQL NULL</span>
<span class="k">return</span> <span class="s1">'NULL'</span><span class="p">,</span> <span class="p">[]</span>
<span class="k">return</span> <span class="s1">'</span><span class="si">%s</span><span class="s1">'</span><span class="p">,</span> <span class="p">[</span><span class="n">val</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">Value</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="n">c</span><span class="o">.</span><span class="n">for_save</span> <span class="o">=</span> <span class="n">for_save</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[]</span></div>
<span class="k">class</span> <span class="nc">DurationValue</span><span class="p">(</span><span class="n">Value</span><span class="p">):</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span><span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">has_native_duration_field</span> <span class="ow">and</span>
<span class="n">connection</span><span class="o">.</span><span class="n">features</span><span class="o">.</span><span class="n">driver_supports_timedelta_args</span><span class="p">):</span>
<span class="k">return</span> <span class="nb">super</span><span class="p">(</span><span class="n">DurationValue</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">as_sql</span><span class="p">(</span><span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="k">return</span> <span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">date_interval_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">value</span><span class="p">)</span>
<div class="viewcode-block" id="RawSQL"><a class="viewcode-back" href="../../../../ref/models/expressions.html#django.db.models.expressions.RawSQL">[docs]</a><span class="k">class</span> <span class="nc">RawSQL</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</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">sql</span><span class="p">,</span> <span class="n">params</span><span class="p">,</span> <span class="n">output_field</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="k">if</span> <span class="n">output_field</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">output_field</span> <span class="o">=</span> <span class="n">fields</span><span class="o">.</span><span class="n">Field</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">sql</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">params</span> <span class="o">=</span> <span class="n">sql</span><span class="p">,</span> <span class="n">params</span>
<span class="nb">super</span><span class="p">(</span><span class="n">RawSQL</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">output_field</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">params</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">return</span> <span class="s1">'(</span><span class="si">%s</span><span class="s1">)'</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">sql</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">params</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="p">]</span></div>
<span class="k">class</span> <span class="nc">Star</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"'*'"</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">return</span> <span class="s1">'*'</span><span class="p">,</span> <span class="p">[]</span>
<span class="k">class</span> <span class="nc">Random</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</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="nb">super</span><span class="p">(</span><span class="n">Random</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">fields</span><span class="o">.</span><span class="n">FloatField</span><span class="p">())</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"Random()"</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">return</span> <span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">random_function_sql</span><span class="p">(),</span> <span class="p">[]</span>
<span class="k">class</span> <span class="nc">Col</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</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">alias</span><span class="p">,</span> <span class="n">target</span><span class="p">,</span> <span class="n">output_field</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="k">if</span> <span class="n">output_field</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">output_field</span> <span class="o">=</span> <span class="n">target</span>
<span class="nb">super</span><span class="p">(</span><span class="n">Col</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">output_field</span><span class="p">)</span>
<span class="bp">self</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">target</span> <span class="o">=</span> <span class="n">alias</span><span class="p">,</span> <span class="n">target</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</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">target</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="n">qn</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">quote_name_unless_alias</span>
<span class="k">return</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="n">qn</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">alias</span><span class="p">),</span> <span class="n">qn</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">target</span><span class="o">.</span><span class="n">column</span><span class="p">)),</span> <span class="p">[]</span>
<span class="k">def</span> <span class="nf">relabeled_clone</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">relabels</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="p">(</span><span class="n">relabels</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="bp">self</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">alias</span><span class="p">),</span> <span class="bp">self</span><span class="o">.</span><span class="n">target</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">get_db_converters</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="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">target</span> <span class="o">==</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="p">:</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="o">.</span><span class="n">get_db_converters</span><span class="p">(</span><span class="n">connection</span><span class="p">)</span>
<span class="k">return</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="o">.</span><span class="n">get_db_converters</span><span class="p">(</span><span class="n">connection</span><span class="p">)</span> <span class="o">+</span>
<span class="bp">self</span><span class="o">.</span><span class="n">target</span><span class="o">.</span><span class="n">get_db_converters</span><span class="p">(</span><span class="n">connection</span><span class="p">))</span>
<span class="k">class</span> <span class="nc">Ref</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Reference to column alias of the query. For example, Ref('sum_cost') in</span>
<span class="sd"> qs.annotate(sum_cost=Sum('cost')) query.</span>
<span class="sd"> """</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">refs</span><span class="p">,</span> <span class="n">source</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">Ref</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">refs</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">source</span> <span class="o">=</span> <span class="n">refs</span><span class="p">,</span> <span class="n">source</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">refs</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">source</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">source</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">source</span><span class="p">,</span> <span class="o">=</span> <span class="n">exprs</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="c1"># The sub-expression `source` has already been resolved, as this is</span>
<span class="c1"># just a reference to the name of `source`.</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">def</span> <span class="nf">relabeled_clone</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">relabels</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">%s</span><span class="s2">"</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="bp">self</span><span class="o">.</span><span class="n">refs</span><span class="p">),</span> <span class="p">[]</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="p">]</span>
<div class="viewcode-block" id="ExpressionWrapper"><a class="viewcode-back" href="../../../../ref/models/expressions.html#django.db.models.expressions.ExpressionWrapper">[docs]</a><span class="k">class</span> <span class="nc">ExpressionWrapper</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> An expression that can wrap another expression so that it can provide</span>
<span class="sd"> extra context to the inner expression, such as the output_field.</span>
<span class="sd"> """</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">expression</span><span class="p">,</span> <span class="n">output_field</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">ExpressionWrapper</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">output_field</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">expression</span> <span class="o">=</span> <span class="n">expression</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">expression</span> <span class="o">=</span> <span class="n">exprs</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">expression</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">expression</span><span class="o">.</span><span class="n">as_sql</span><span class="p">(</span><span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">expression</span><span class="p">)</span></div>
<div class="viewcode-block" id="When"><a class="viewcode-back" href="../../../../ref/models/conditional-expressions.html#django.db.models.expressions.When">[docs]</a><span class="k">class</span> <span class="nc">When</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="n">template</span> <span class="o">=</span> <span class="s1">'WHEN </span><span class="si">%(condition)s</span><span class="s1"> THEN </span><span class="si">%(result)s</span><span class="s1">'</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">condition</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">then</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="o">**</span><span class="n">lookups</span><span class="p">):</span>
<span class="k">if</span> <span class="n">lookups</span> <span class="ow">and</span> <span class="n">condition</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">condition</span><span class="p">,</span> <span class="n">lookups</span> <span class="o">=</span> <span class="n">Q</span><span class="p">(</span><span class="o">**</span><span class="n">lookups</span><span class="p">),</span> <span class="kc">None</span>
<span class="k">if</span> <span class="n">condition</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">or</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">condition</span><span class="p">,</span> <span class="n">Q</span><span class="p">)</span> <span class="ow">or</span> <span class="n">lookups</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"__init__() takes either a Q object or lookups as keyword arguments"</span><span class="p">)</span>
<span class="nb">super</span><span class="p">(</span><span class="n">When</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="kc">None</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">condition</span> <span class="o">=</span> <span class="n">condition</span>
<span class="bp">self</span><span class="o">.</span><span class="n">result</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parse_expressions</span><span class="p">(</span><span class="n">then</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">__str__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"WHEN </span><span class="si">%r</span><span class="s2"> THEN </span><span class="si">%r</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">condition</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">result</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</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">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">condition</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">result</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">condition</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">result</span> <span class="o">=</span> <span class="n">exprs</span>
<span class="k">def</span> <span class="nf">get_source_fields</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># We're only interested in the fields of the result expressions.</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">result</span><span class="o">.</span><span class="n">_output_field_or_none</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">c</span><span class="o">.</span><span class="n">is_summary</span> <span class="o">=</span> <span class="n">summarize</span>
<span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">c</span><span class="o">.</span><span class="n">condition</span><span class="p">,</span> <span class="s1">'resolve_expression'</span><span class="p">):</span>
<span class="n">c</span><span class="o">.</span><span class="n">condition</span> <span class="o">=</span> <span class="n">c</span><span class="o">.</span><span class="n">condition</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<span class="n">c</span><span class="o">.</span><span class="n">result</span> <span class="o">=</span> <span class="n">c</span><span class="o">.</span><span class="n">result</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">template</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">template_params</span> <span class="o">=</span> <span class="p">{}</span>
<span class="n">sql_params</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">condition_sql</span><span class="p">,</span> <span class="n">condition_params</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">condition</span><span class="p">)</span>
<span class="n">template_params</span><span class="p">[</span><span class="s1">'condition'</span><span class="p">]</span> <span class="o">=</span> <span class="n">condition_sql</span>
<span class="n">sql_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">condition_params</span><span class="p">)</span>
<span class="n">result_sql</span><span class="p">,</span> <span class="n">result_params</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">result</span><span class="p">)</span>
<span class="n">template_params</span><span class="p">[</span><span class="s1">'result'</span><span class="p">]</span> <span class="o">=</span> <span class="n">result_sql</span>
<span class="n">sql_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">result_params</span><span class="p">)</span>
<span class="n">template</span> <span class="o">=</span> <span class="n">template</span> <span class="ow">or</span> <span class="bp">self</span><span class="o">.</span><span class="n">template</span>
<span class="k">return</span> <span class="n">template</span> <span class="o">%</span> <span class="n">template_params</span><span class="p">,</span> <span class="n">sql_params</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># This is not a complete expression and cannot be used in GROUP BY.</span>
<span class="n">cols</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">source</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">():</span>
<span class="n">cols</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">source</span><span class="o">.</span><span class="n">get_group_by_cols</span><span class="p">())</span>
<span class="k">return</span> <span class="n">cols</span></div>
<div class="viewcode-block" id="Case"><a class="viewcode-back" href="../../../../ref/models/conditional-expressions.html#django.db.models.expressions.Case">[docs]</a><span class="k">class</span> <span class="nc">Case</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> An SQL searched CASE expression:</span>
<span class="sd"> CASE</span>
<span class="sd"> WHEN n > 0</span>
<span class="sd"> THEN 'positive'</span>
<span class="sd"> WHEN n < 0</span>
<span class="sd"> THEN 'negative'</span>
<span class="sd"> ELSE 'zero'</span>
<span class="sd"> END</span>
<span class="sd"> """</span>
<span class="n">template</span> <span class="o">=</span> <span class="s1">'CASE </span><span class="si">%(cases)s</span><span class="s1"> ELSE </span><span class="si">%(default)s</span><span class="s1"> END'</span>
<span class="n">case_joiner</span> <span class="o">=</span> <span class="s1">' '</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="o">*</span><span class="n">cases</span><span class="p">,</span> <span class="o">**</span><span class="n">extra</span><span class="p">):</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">all</span><span class="p">(</span><span class="nb">isinstance</span><span class="p">(</span><span class="n">case</span><span class="p">,</span> <span class="n">When</span><span class="p">)</span> <span class="k">for</span> <span class="n">case</span> <span class="ow">in</span> <span class="n">cases</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s2">"Positional arguments must all be When objects."</span><span class="p">)</span>
<span class="n">default</span> <span class="o">=</span> <span class="n">extra</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'default'</span><span class="p">,</span> <span class="kc">None</span><span class="p">)</span>
<span class="n">output_field</span> <span class="o">=</span> <span class="n">extra</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'output_field'</span><span class="p">,</span> <span class="kc">None</span><span class="p">)</span>
<span class="nb">super</span><span class="p">(</span><span class="n">Case</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">cases</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">cases</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">default</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parse_expressions</span><span class="p">(</span><span class="n">default</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">__str__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"CASE </span><span class="si">%s</span><span class="s2">, ELSE </span><span class="si">%r</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span><span class="s1">', '</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="nb">str</span><span class="p">(</span><span class="n">c</span><span class="p">)</span> <span class="k">for</span> <span class="n">c</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">cases</span><span class="p">),</span> <span class="bp">self</span><span class="o">.</span><span class="n">default</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</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">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">cases</span> <span class="o">+</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">default</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">cases</span> <span class="o">=</span> <span class="n">exprs</span><span class="p">[:</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">default</span> <span class="o">=</span> <span class="n">exprs</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">c</span><span class="o">.</span><span class="n">is_summary</span> <span class="o">=</span> <span class="n">summarize</span>
<span class="k">for</span> <span class="n">pos</span><span class="p">,</span> <span class="n">case</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">c</span><span class="o">.</span><span class="n">cases</span><span class="p">):</span>
<span class="n">c</span><span class="o">.</span><span class="n">cases</span><span class="p">[</span><span class="n">pos</span><span class="p">]</span> <span class="o">=</span> <span class="n">case</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="n">c</span><span class="o">.</span><span class="n">default</span> <span class="o">=</span> <span class="n">c</span><span class="o">.</span><span class="n">default</span><span class="o">.</span><span class="n">resolve_expression</span><span class="p">(</span><span class="n">query</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">,</span> <span class="n">for_save</span><span class="p">)</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">copy</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">c</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">Case</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">c</span><span class="o">.</span><span class="n">cases</span> <span class="o">=</span> <span class="n">c</span><span class="o">.</span><span class="n">cases</span><span class="p">[:]</span>
<span class="k">return</span> <span class="n">c</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">template</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">extra</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">cases</span><span class="p">:</span>
<span class="k">return</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">default</span><span class="p">)</span>
<span class="n">template_params</span> <span class="o">=</span> <span class="nb">dict</span><span class="p">(</span><span class="n">extra</span><span class="p">)</span> <span class="k">if</span> <span class="n">extra</span> <span class="k">else</span> <span class="p">{}</span>
<span class="n">case_parts</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">sql_params</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">case</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">cases</span><span class="p">:</span>
<span class="n">case_sql</span><span class="p">,</span> <span class="n">case_params</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="n">case</span><span class="p">)</span>
<span class="n">case_parts</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">case_sql</span><span class="p">)</span>
<span class="n">sql_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">case_params</span><span class="p">)</span>
<span class="n">template_params</span><span class="p">[</span><span class="s1">'cases'</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">case_joiner</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">case_parts</span><span class="p">)</span>
<span class="n">default_sql</span><span class="p">,</span> <span class="n">default_params</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">default</span><span class="p">)</span>
<span class="n">template_params</span><span class="p">[</span><span class="s1">'default'</span><span class="p">]</span> <span class="o">=</span> <span class="n">default_sql</span>
<span class="n">sql_params</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">default_params</span><span class="p">)</span>
<span class="n">template</span> <span class="o">=</span> <span class="n">template</span> <span class="ow">or</span> <span class="bp">self</span><span class="o">.</span><span class="n">template</span>
<span class="n">sql</span> <span class="o">=</span> <span class="n">template</span> <span class="o">%</span> <span class="n">template_params</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_output_field_or_none</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="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">unification_cast_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">output_field</span><span class="p">)</span> <span class="o">%</span> <span class="n">sql</span>
<span class="k">return</span> <span class="n">sql</span><span class="p">,</span> <span class="n">sql_params</span></div>
<span class="k">class</span> <span class="nc">Date</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Add a date selection column.</span>
<span class="sd"> """</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">lookup</span><span class="p">,</span> <span class="n">lookup_type</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">Date</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">fields</span><span class="o">.</span><span class="n">DateField</span><span class="p">())</span>
<span class="bp">self</span><span class="o">.</span><span class="n">lookup</span> <span class="o">=</span> <span class="n">lookup</span>
<span class="bp">self</span><span class="o">.</span><span class="n">col</span> <span class="o">=</span> <span class="kc">None</span>
<span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span> <span class="o">=</span> <span class="n">lookup_type</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">col</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">col</span><span class="p">,</span> <span class="o">=</span> <span class="n">exprs</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">copy</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">copy</span><span class="o">.</span><span class="n">col</span> <span class="o">=</span> <span class="n">query</span><span class="o">.</span><span class="n">resolve_ref</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lookup</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">)</span>
<span class="n">field</span> <span class="o">=</span> <span class="n">copy</span><span class="o">.</span><span class="n">col</span><span class="o">.</span><span class="n">output_field</span>
<span class="k">assert</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">field</span><span class="p">,</span> <span class="n">fields</span><span class="o">.</span><span class="n">DateField</span><span class="p">),</span> <span class="s2">"</span><span class="si">%r</span><span class="s2"> isn't a DateField."</span> <span class="o">%</span> <span class="n">field</span><span class="o">.</span><span class="n">name</span>
<span class="k">if</span> <span class="n">settings</span><span class="o">.</span><span class="n">USE_TZ</span><span class="p">:</span>
<span class="k">assert</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">field</span><span class="p">,</span> <span class="n">fields</span><span class="o">.</span><span class="n">DateTimeField</span><span class="p">),</span> <span class="p">(</span>
<span class="s2">"</span><span class="si">%r</span><span class="s2"> is a DateTimeField, not a DateField."</span> <span class="o">%</span> <span class="n">field</span><span class="o">.</span><span class="n">name</span>
<span class="p">)</span>
<span class="k">return</span> <span class="n">copy</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</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="bp">self</span><span class="o">.</span><span class="n">col</span><span class="o">.</span><span class="n">as_sql</span><span class="p">(</span><span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="k">assert</span> <span class="ow">not</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
<span class="k">return</span> <span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">date_trunc_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span><span class="p">,</span> <span class="n">sql</span><span class="p">),</span> <span class="p">[]</span>
<span class="k">def</span> <span class="nf">copy</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">copy</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">Date</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">copy</span><span class="o">.</span><span class="n">lookup</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup</span>
<span class="n">copy</span><span class="o">.</span><span class="n">lookup_type</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span>
<span class="k">return</span> <span class="n">copy</span>
<span class="k">def</span> <span class="nf">convert_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="n">expression</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">datetime</span><span class="o">.</span><span class="n">datetime</span><span class="p">):</span>
<span class="n">value</span> <span class="o">=</span> <span class="n">value</span><span class="o">.</span><span class="n">date</span><span class="p">()</span>
<span class="k">return</span> <span class="n">value</span>
<span class="k">class</span> <span class="nc">DateTime</span><span class="p">(</span><span class="n">Expression</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Add a datetime selection column.</span>
<span class="sd"> """</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">lookup</span><span class="p">,</span> <span class="n">lookup_type</span><span class="p">,</span> <span class="n">tzinfo</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">DateTime</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="n">output_field</span><span class="o">=</span><span class="n">fields</span><span class="o">.</span><span class="n">DateTimeField</span><span class="p">())</span>
<span class="bp">self</span><span class="o">.</span><span class="n">lookup</span> <span class="o">=</span> <span class="n">lookup</span>
<span class="bp">self</span><span class="o">.</span><span class="n">col</span> <span class="o">=</span> <span class="kc">None</span>
<span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span> <span class="o">=</span> <span class="n">lookup_type</span>
<span class="k">if</span> <span class="n">tzinfo</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">tzname</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">tzname</span> <span class="o">=</span> <span class="n">timezone</span><span class="o">.</span><span class="n">_get_timezone_name</span><span class="p">(</span><span class="n">tzinfo</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">tzinfo</span> <span class="o">=</span> <span class="n">tzinfo</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">, </span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">tzinfo</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">col</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">col</span><span class="p">,</span> <span class="o">=</span> <span class="n">exprs</span>
<span class="k">def</span> <span class="nf">resolve_expression</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">query</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">allow_joins</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">reuse</span><span class="o">=</span><span class="kc">None</span><span class="p">,</span> <span class="n">summarize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">for_save</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
<span class="n">copy</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">copy</span><span class="o">.</span><span class="n">col</span> <span class="o">=</span> <span class="n">query</span><span class="o">.</span><span class="n">resolve_ref</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lookup</span><span class="p">,</span> <span class="n">allow_joins</span><span class="p">,</span> <span class="n">reuse</span><span class="p">,</span> <span class="n">summarize</span><span class="p">)</span>
<span class="n">field</span> <span class="o">=</span> <span class="n">copy</span><span class="o">.</span><span class="n">col</span><span class="o">.</span><span class="n">output_field</span>
<span class="k">assert</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">field</span><span class="p">,</span> <span class="n">fields</span><span class="o">.</span><span class="n">DateTimeField</span><span class="p">),</span> <span class="p">(</span>
<span class="s2">"</span><span class="si">%r</span><span class="s2"> isn't a DateTimeField."</span> <span class="o">%</span> <span class="n">field</span><span class="o">.</span><span class="n">name</span>
<span class="p">)</span>
<span class="k">return</span> <span class="n">copy</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</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="bp">self</span><span class="o">.</span><span class="n">col</span><span class="o">.</span><span class="n">as_sql</span><span class="p">(</span><span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">)</span>
<span class="k">assert</span> <span class="ow">not</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
<span class="k">return</span> <span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">datetime_trunc_sql</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span><span class="p">,</span> <span class="n">sql</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">tzname</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">copy</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">copy</span> <span class="o">=</span> <span class="nb">super</span><span class="p">(</span><span class="n">DateTime</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="n">copy</span><span class="o">.</span><span class="n">lookup</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup</span>
<span class="n">copy</span><span class="o">.</span><span class="n">lookup_type</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">lookup_type</span>
<span class="n">copy</span><span class="o">.</span><span class="n">tzname</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">tzname</span>
<span class="k">return</span> <span class="n">copy</span>
<span class="k">def</span> <span class="nf">convert_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="n">expression</span><span class="p">,</span> <span class="n">connection</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="k">if</span> <span class="n">settings</span><span class="o">.</span><span class="n">USE_TZ</span><span class="p">:</span>
<span class="k">if</span> <span class="n">value</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">"Database returned an invalid value in QuerySet.datetimes(). "</span>
<span class="s2">"Are time zone definitions for your database and pytz installed?"</span>
<span class="p">)</span>
<span class="n">value</span> <span class="o">=</span> <span class="n">value</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="n">tzinfo</span><span class="o">=</span><span class="kc">None</span><span class="p">)</span>
<span class="n">value</span> <span class="o">=</span> <span class="n">timezone</span><span class="o">.</span><span class="n">make_aware</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">tzinfo</span><span class="p">)</span>
<span class="k">return</span> <span class="n">value</span>
<span class="k">class</span> <span class="nc">OrderBy</span><span class="p">(</span><span class="n">BaseExpression</span><span class="p">):</span>
<span class="n">template</span> <span class="o">=</span> <span class="s1">'</span><span class="si">%(expression)s</span><span class="s1"> </span><span class="si">%(ordering)s</span><span class="s1">'</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">expression</span><span class="p">,</span> <span class="n">descending</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">descending</span> <span class="o">=</span> <span class="n">descending</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">expression</span><span class="p">,</span> <span class="s1">'resolve_expression'</span><span class="p">):</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">'expression must be an expression type'</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">expression</span> <span class="o">=</span> <span class="n">expression</span>
<span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="s2">"</span><span class="si">{}</span><span class="s2">(</span><span class="si">{}</span><span class="s2">, descending=</span><span class="si">{}</span><span class="s2">)"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">__class__</span><span class="o">.</span><span class="n">__name__</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">expression</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">descending</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">set_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exprs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">expression</span> <span class="o">=</span> <span class="n">exprs</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">get_source_expressions</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">return</span> <span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">expression</span><span class="p">]</span>
<span class="k">def</span> <span class="nf">as_sql</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">compiler</span><span class="p">,</span> <span class="n">connection</span><span class="p">):</span>
<span class="n">connection</span><span class="o">.</span><span class="n">ops</span><span class="o">.</span><span class="n">check_expression_support</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
<span class="n">expression_sql</span><span class="p">,</span> <span class="n">params</span> <span class="o">=</span> <span class="n">compiler</span><span class="o">.</span><span class="n">compile</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">expression</span><span class="p">)</span>
<span class="n">placeholders</span> <span class="o">=</span> <span class="p">{</span><span class="s1">'expression'</span><span class="p">:</span> <span class="n">expression_sql</span><span class="p">}</span>
<span class="n">placeholders</span><span class="p">[</span><span class="s1">'ordering'</span><span class="p">]</span> <span class="o">=</span> <span class="s1">'DESC'</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">descending</span> <span class="k">else</span> <span class="s1">'ASC'</span>
<span class="k">return</span> <span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">template</span> <span class="o">%</span> <span class="n">placeholders</span><span class="p">)</span><span class="o">.</span><span class="n">rstrip</span><span class="p">(),</span> <span class="n">params</span>
<span class="k">def</span> <span class="nf">get_group_by_cols</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">cols</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">source</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">get_source_expressions</span><span class="p">():</span>
<span class="n">cols</span><span class="o">.</span><span class="n">extend</span><span class="p">(</span><span class="n">source</span><span class="o">.</span><span class="n">get_group_by_cols</span><span class="p">())</span>
<span class="k">return</span> <span class="n">cols</span>
<span class="k">def</span> <span class="nf">reverse_ordering</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">descending</span> <span class="o">=</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">descending</span>
<span class="k">return</span> <span class="bp">self</span>
<span class="k">def</span> <span class="nf">asc</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">descending</span> <span class="o">=</span> <span class="kc">False</span>
<span class="k">def</span> <span class="nf">desc</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">descending</span> <span class="o">=</span> <span class="kc">True</span>
</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.models.expressions</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>
<h3>Last update:</h3>
<p class="topless">Mar 10, 2018</p>
</div>
</div>
<div id="ft">
<div class="nav">
<a href="../../../index.html" title="Module code" accesskey="U">up</a></div>
</div>
</div>
<div class="clearer"></div>
</div>
</body>
</html>
distrib
>
Mageia
>
6
>
armv7hl
>
media
>
core-updates
>
by-pkgid
>
65530c6176058f9b54858c3b4f6385e6
>
files
>
97
