<!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>Lookup API reference — 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="Models" href="index.html" /> <link rel="next" title="Query Expressions" href="expressions.html" /> <link rel="prev" title="QuerySet API reference" href="querysets.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 = "../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="querysets.html" title="QuerySet API reference">previous</a> | <a href="../index.html" title="API Reference" accesskey="U">up</a> | <a href="expressions.html" title="Query Expressions">next</a> »</div> </div> <div id="bd"> <div id="yui-main"> <div class="yui-b"> <div class="yui-g" id="ref-models-lookups"> <div class="section" id="s-module-django.db.models.lookups"> <span id="s-lookup-api-reference"></span><span id="module-django.db.models.lookups"></span><span id="lookup-api-reference"></span><h1>Lookup API reference<a class="headerlink" href="#module-django.db.models.lookups" title="Permalink to this headline">¶</a></h1> <div class="versionadded"> <span class="title">New in Django 1.7.</span> </div> <p>This document has the API references of lookups, the Django API for building the <code class="docutils literal"><span class="pre">WHERE</span></code> clause of a database query. To learn how to <em>use</em> lookups, see <a class="reference internal" href="../../topics/db/queries.html"><span class="doc">Making queries</span></a>; to learn how to <em>create</em> new lookups, see <a class="reference internal" href="../../howto/custom-lookups.html"><span class="doc">Custom Lookups</span></a>.</p> <p>The lookup API has two components: a <a class="reference internal" href="#django.db.models.lookups.RegisterLookupMixin" title="django.db.models.lookups.RegisterLookupMixin"><code class="xref py py-class docutils literal"><span class="pre">RegisterLookupMixin</span></code></a> class that registers lookups, and the <a class="reference internal" href="#query-expression"><span class="std std-ref">Query Expression API</span></a>, a set of methods that a class has to implement to be registrable as a lookup.</p> <p>Django has two base classes that follow the query expression API and from where all Django builtin lookups are derived:</p> <ul class="simple"> <li><a class="reference internal" href="#django.db.models.Lookup" title="django.db.models.Lookup"><code class="xref py py-class docutils literal"><span class="pre">Lookup</span></code></a>: to lookup a field (e.g. the <code class="docutils literal"><span class="pre">exact</span></code> of <code class="docutils literal"><span class="pre">field_name__exact</span></code>)</li> <li><a class="reference internal" href="#django.db.models.Transform" title="django.db.models.Transform"><code class="xref py py-class docutils literal"><span class="pre">Transform</span></code></a>: to transform a field</li> </ul> <p>A lookup expression consists of three parts:</p> <ul class="simple"> <li>Fields part (e.g. <code class="docutils literal"><span class="pre">Book.objects.filter(author__best_friends__first_name...</span></code>);</li> <li>Transforms part (may be omitted) (e.g. <code class="docutils literal"><span class="pre">__lower__first3chars__reversed</span></code>);</li> <li>A lookup (e.g. <code class="docutils literal"><span class="pre">__icontains</span></code>) that, if omitted, defaults to <code class="docutils literal"><span class="pre">__exact</span></code>.</li> </ul> <div class="section" id="s-registration-api"> <span id="s-lookup-registration-api"></span><span id="registration-api"></span><span id="lookup-registration-api"></span><h2>Registration API<a class="headerlink" href="#registration-api" title="Permalink to this headline">¶</a></h2> <p>Django uses <a class="reference internal" href="#django.db.models.lookups.RegisterLookupMixin" title="django.db.models.lookups.RegisterLookupMixin"><code class="xref py py-class docutils literal"><span class="pre">RegisterLookupMixin</span></code></a> to give a class the interface to register lookups on itself. The two prominent examples are <a class="reference internal" href="fields.html#django.db.models.Field" title="django.db.models.Field"><code class="xref py py-class docutils literal"><span class="pre">Field</span></code></a>, the base class of all model fields, and <code class="docutils literal"><span class="pre">Aggregate</span></code>, the base class of all Django aggregates.</p> <dl class="class"> <dt id="django.db.models.lookups.RegisterLookupMixin"> <em class="property">class </em><code class="descclassname">lookups.</code><code class="descname">RegisterLookupMixin</code><a class="headerlink" href="#django.db.models.lookups.RegisterLookupMixin" title="Permalink to this definition">¶</a></dt> <dd><p>A mixin that implements the lookup API on a class.</p> <dl class="classmethod"> <dt id="django.db.models.lookups.RegisterLookupMixin.register_lookup"> <em class="property">classmethod </em><code class="descname">register_lookup</code>(<em>lookup</em>)<a class="headerlink" href="#django.db.models.lookups.RegisterLookupMixin.register_lookup" title="Permalink to this definition">¶</a></dt> <dd><p>Registers a new lookup in the class. For example <code class="docutils literal"><span class="pre">DateField.register_lookup(YearExact)</span></code> will register <code class="docutils literal"><span class="pre">YearExact</span></code> lookup on <code class="docutils literal"><span class="pre">DateField</span></code>. It overrides a lookup that already exists with the same name.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.lookups.RegisterLookupMixin.get_lookup"> <code class="descname">get_lookup</code>(<em>lookup_name</em>)<a class="headerlink" href="#django.db.models.lookups.RegisterLookupMixin.get_lookup" title="Permalink to this definition">¶</a></dt> <dd><p>Returns the <a class="reference internal" href="#django.db.models.Lookup" title="django.db.models.Lookup"><code class="xref py py-class docutils literal"><span class="pre">Lookup</span></code></a> named <code class="docutils literal"><span class="pre">lookup_name</span></code> registered in the class. The default implementation looks recursively on all parent classes and checks if any has a registered lookup named <code class="docutils literal"><span class="pre">lookup_name</span></code>, returning the first match.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.lookups.RegisterLookupMixin.get_transform"> <code class="descname">get_transform</code>(<em>transform_name</em>)<a class="headerlink" href="#django.db.models.lookups.RegisterLookupMixin.get_transform" title="Permalink to this definition">¶</a></dt> <dd><p>Returns a <a class="reference internal" href="#django.db.models.Transform" title="django.db.models.Transform"><code class="xref py py-class docutils literal"><span class="pre">Transform</span></code></a> named <code class="docutils literal"><span class="pre">transform_name</span></code>. The default implementation looks recursively on all parent classes to check if any has the registered transform named <code class="docutils literal"><span class="pre">transform_name</span></code>, returning the first match.</p> </dd></dl> </dd></dl> <p>For a class to be a lookup, it must follow the <a class="reference internal" href="#query-expression"><span class="std std-ref">Query Expression API</span></a>. <a class="reference internal" href="#django.db.models.Lookup" title="django.db.models.Lookup"><code class="xref py py-class docutils literal"><span class="pre">Lookup</span></code></a> and <a class="reference internal" href="#django.db.models.Transform" title="django.db.models.Transform"><code class="xref py py-class docutils literal"><span class="pre">Transform</span></code></a> naturally follow this API.</p> </div> <div class="section" id="s-the-query-expression-api"> <span id="s-query-expression"></span><span id="the-query-expression-api"></span><span id="query-expression"></span><h2>The Query Expression API<a class="headerlink" href="#the-query-expression-api" title="Permalink to this headline">¶</a></h2> <p>The query expression API is a common set of methods that classes define to be usable in query expressions to translate themselves into SQL expressions. Direct field references, aggregates, and <code class="docutils literal"><span class="pre">Transform</span></code> are examples that follow this API. A class is said to follow the query expression API when it implements the following methods:</p> <dl class="method"> <dt id="django.db.models.as_sql"> <code class="descname">as_sql</code>(<em>self</em>, <em>compiler</em>, <em>connection</em>)<a class="headerlink" href="#django.db.models.as_sql" title="Permalink to this definition">¶</a></dt> <dd><p>Responsible for producing the query string and parameters for the expression. The <code class="docutils literal"><span class="pre">compiler</span></code> is an <code class="docutils literal"><span class="pre">SQLCompiler</span></code> object, which has a <code class="docutils literal"><span class="pre">compile()</span></code> method that can be used to compile other expressions. The <code class="docutils literal"><span class="pre">connection</span></code> is the connection used to execute the query.</p> <p>Calling <code class="docutils literal"><span class="pre">expression.as_sql()</span></code> is usually incorrect - instead <code class="docutils literal"><span class="pre">compiler.compile(expression)</span></code> should be used. The <code class="docutils literal"><span class="pre">compiler.compile()</span></code> method will take care of calling vendor-specific methods of the expression.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.as_vendorname"> <code class="descname">as_vendorname</code>(<em>self</em>, <em>compiler</em>, <em>connection</em>)<a class="headerlink" href="#django.db.models.as_vendorname" title="Permalink to this definition">¶</a></dt> <dd><p>Works like <code class="docutils literal"><span class="pre">as_sql()</span></code> method. When an expression is compiled by <code class="docutils literal"><span class="pre">compiler.compile()</span></code>, Django will first try to call <code class="docutils literal"><span class="pre">as_vendorname()</span></code>, where <code class="docutils literal"><span class="pre">vendorname</span></code> is the vendor name of the backend used for executing the query. The <code class="docutils literal"><span class="pre">vendorname</span></code> is one of <code class="docutils literal"><span class="pre">postgresql</span></code>, <code class="docutils literal"><span class="pre">oracle</span></code>, <code class="docutils literal"><span class="pre">sqlite</span></code>, or <code class="docutils literal"><span class="pre">mysql</span></code> for Django’s built-in backends.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.get_lookup"> <code class="descname">get_lookup</code>(<em>lookup_name</em>)<a class="headerlink" href="#django.db.models.get_lookup" title="Permalink to this definition">¶</a></dt> <dd><p>Must return the lookup named <code class="docutils literal"><span class="pre">lookup_name</span></code>. For instance, by returning <code class="docutils literal"><span class="pre">self.output_field.get_lookup(lookup_name)</span></code>.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.get_transform"> <code class="descname">get_transform</code>(<em>transform_name</em>)<a class="headerlink" href="#django.db.models.get_transform" title="Permalink to this definition">¶</a></dt> <dd><p>Must return the lookup named <code class="docutils literal"><span class="pre">transform_name</span></code>. For instance, by returning <code class="docutils literal"><span class="pre">self.output_field.get_transform(transform_name)</span></code>.</p> </dd></dl> <dl class="attribute"> <dt id="django.db.models.output_field"> <code class="descname">output_field</code><a class="headerlink" href="#django.db.models.output_field" title="Permalink to this definition">¶</a></dt> <dd><p>Defines the type of class returned by the <code class="docutils literal"><span class="pre">get_lookup()</span></code> method. It must be a <a class="reference internal" href="fields.html#django.db.models.Field" title="django.db.models.Field"><code class="xref py py-class docutils literal"><span class="pre">Field</span></code></a> instance.</p> </dd></dl> </div> <div class="section" id="s-transform-reference"> <span id="transform-reference"></span><h2>Transform reference<a class="headerlink" href="#transform-reference" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.Transform"> <em class="property">class </em><code class="descname">Transform</code><a class="reference internal" href="../../_modules/django/db/models/lookups.html#Transform"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.Transform" title="Permalink to this definition">¶</a></dt> <dd><p>A <code class="docutils literal"><span class="pre">Transform</span></code> is a generic class to implement field transformations. A prominent example is <code class="docutils literal"><span class="pre">__year</span></code> that transforms a <code class="docutils literal"><span class="pre">DateField</span></code> into a <code class="docutils literal"><span class="pre">IntegerField</span></code>.</p> <p>The notation to use a <code class="docutils literal"><span class="pre">Transform</span></code> in an lookup expression is <code class="docutils literal"><span class="pre"><expression>__<transformation></span></code> (e.g. <code class="docutils literal"><span class="pre">date__year</span></code>).</p> <p>This class follows the <a class="reference internal" href="#query-expression"><span class="std std-ref">Query Expression API</span></a>, which implies that you can use <code class="docutils literal"><span class="pre"><expression>__<transform1>__<transform2></span></code>.</p> <dl class="attribute"> <dt id="django.db.models.Transform.bilateral"> <code class="descname">bilateral</code><a class="headerlink" href="#django.db.models.Transform.bilateral" title="Permalink to this definition">¶</a></dt> <dd><div class="versionadded"> <span class="title">New in Django 1.8.</span> </div> <p>A boolean indicating whether this transformation should apply to both <code class="docutils literal"><span class="pre">lhs</span></code> and <code class="docutils literal"><span class="pre">rhs</span></code>. Bilateral transformations will be applied to <code class="docutils literal"><span class="pre">rhs</span></code> in the same order as they appear in the lookup expression. By default it is set to <code class="docutils literal"><span class="pre">False</span></code>. For example usage, see <a class="reference internal" href="../../howto/custom-lookups.html"><span class="doc">Custom Lookups</span></a>.</p> </dd></dl> <dl class="attribute"> <dt id="django.db.models.Transform.lhs"> <code class="descname">lhs</code><a class="headerlink" href="#django.db.models.Transform.lhs" title="Permalink to this definition">¶</a></dt> <dd><p>The left-hand side - what is being transformed. It must follow the <a class="reference internal" href="#query-expression"><span class="std std-ref">Query Expression API</span></a>.</p> </dd></dl> <dl class="attribute"> <dt id="django.db.models.Transform.lookup_name"> <code class="descname">lookup_name</code><a class="headerlink" href="#django.db.models.Transform.lookup_name" title="Permalink to this definition">¶</a></dt> <dd><p>The name of the lookup, used for identifying it on parsing query expressions. It cannot contain the string <code class="docutils literal"><span class="pre">"__"</span></code>.</p> </dd></dl> <dl class="attribute"> <dt id="django.db.models.Transform.output_field"> <code class="descname">output_field</code><a class="headerlink" href="#django.db.models.Transform.output_field" title="Permalink to this definition">¶</a></dt> <dd><p>Defines the class this transformation outputs. It must be a <a class="reference internal" href="fields.html#django.db.models.Field" title="django.db.models.Field"><code class="xref py py-class docutils literal"><span class="pre">Field</span></code></a> instance. By default is the same as its <code class="docutils literal"><span class="pre">lhs.output_field</span></code>.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.Transform.as_sql"> <code class="descname">as_sql</code>()<a class="reference internal" href="../../_modules/django/db/models/lookups.html#Transform.as_sql"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.Transform.as_sql" title="Permalink to this definition">¶</a></dt> <dd><p>To be overridden; raises <code class="xref py py-exc docutils literal"><span class="pre">NotImplementedError</span></code>.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.Transform.get_lookup"> <code class="descname">get_lookup</code>(<em>lookup_name</em>)<a class="headerlink" href="#django.db.models.Transform.get_lookup" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <a class="reference internal" href="#django.db.models.lookups.RegisterLookupMixin.get_lookup" title="django.db.models.lookups.RegisterLookupMixin.get_lookup"><code class="xref py py-meth docutils literal"><span class="pre">get_lookup()</span></code></a>.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.Transform.get_transform"> <code class="descname">get_transform</code>(<em>transform_name</em>)<a class="headerlink" href="#django.db.models.Transform.get_transform" title="Permalink to this definition">¶</a></dt> <dd><p>Same as <a class="reference internal" href="#django.db.models.lookups.RegisterLookupMixin.get_transform" title="django.db.models.lookups.RegisterLookupMixin.get_transform"><code class="xref py py-meth docutils literal"><span class="pre">get_transform()</span></code></a>.</p> </dd></dl> </dd></dl> </div> <div class="section" id="s-lookup-reference"> <span id="lookup-reference"></span><h2>Lookup reference<a class="headerlink" href="#lookup-reference" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.Lookup"> <em class="property">class </em><code class="descname">Lookup</code><a class="reference internal" href="../../_modules/django/db/models/lookups.html#Lookup"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.Lookup" title="Permalink to this definition">¶</a></dt> <dd><p>A <code class="docutils literal"><span class="pre">Lookup</span></code> is a generic class to implement lookups. A lookup is a query expression with a left-hand side, <a class="reference internal" href="#django.db.models.Lookup.lhs" title="django.db.models.Lookup.lhs"><code class="xref py py-attr docutils literal"><span class="pre">lhs</span></code></a>; a right-hand side, <a class="reference internal" href="#django.db.models.Lookup.rhs" title="django.db.models.Lookup.rhs"><code class="xref py py-attr docutils literal"><span class="pre">rhs</span></code></a>; and a <code class="docutils literal"><span class="pre">lookup_name</span></code> that is used to produce a boolean comparison between <code class="docutils literal"><span class="pre">lhs</span></code> and <code class="docutils literal"><span class="pre">rhs</span></code> such as <code class="docutils literal"><span class="pre">lhs</span> <span class="pre">in</span> <span class="pre">rhs</span></code> or <code class="docutils literal"><span class="pre">lhs</span> <span class="pre">></span> <span class="pre">rhs</span></code>.</p> <p>The notation to use a lookup in an expression is <code class="docutils literal"><span class="pre"><lhs>__<lookup_name>=<rhs></span></code>.</p> <p>This class doesn’t follow the <a class="reference internal" href="#query-expression"><span class="std std-ref">Query Expression API</span></a> since it has <code class="docutils literal"><span class="pre">=<rhs></span></code> on its construction: lookups are always the end of a lookup expression.</p> <dl class="attribute"> <dt id="django.db.models.Lookup.lhs"> <code class="descname">lhs</code><a class="headerlink" href="#django.db.models.Lookup.lhs" title="Permalink to this definition">¶</a></dt> <dd><p>The left-hand side - what is being looked up. The object must follow the <a class="reference internal" href="#query-expression"><span class="std std-ref">Query Expression API</span></a>.</p> </dd></dl> <dl class="attribute"> <dt id="django.db.models.Lookup.rhs"> <code class="descname">rhs</code><a class="headerlink" href="#django.db.models.Lookup.rhs" title="Permalink to this definition">¶</a></dt> <dd><p>The right-hand side - what <code class="docutils literal"><span class="pre">lhs</span></code> is being compared against. It can be a plain value, or something that compiles into SQL, typically an <code class="docutils literal"><span class="pre">F()</span></code> object or a <code class="docutils literal"><span class="pre">QuerySet</span></code>.</p> </dd></dl> <dl class="attribute"> <dt id="django.db.models.Lookup.lookup_name"> <code class="descname">lookup_name</code><a class="headerlink" href="#django.db.models.Lookup.lookup_name" title="Permalink to this definition">¶</a></dt> <dd><p>The name of this lookup, used to identify it on parsing query expressions. It cannot contain the string <code class="docutils literal"><span class="pre">"__"</span></code>.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.Lookup.process_lhs"> <code class="descname">process_lhs</code>(<em>compiler</em>, <em>connection</em>, <em>lhs=None</em>)<a class="reference internal" href="../../_modules/django/db/models/lookups.html#Lookup.process_lhs"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.Lookup.process_lhs" title="Permalink to this definition">¶</a></dt> <dd><p>Returns a tuple <code class="docutils literal"><span class="pre">(lhs_string,</span> <span class="pre">lhs_params)</span></code>, as returned by <code class="docutils literal"><span class="pre">compiler.compile(lhs)</span></code>. This method can be overridden to tune how the <code class="docutils literal"><span class="pre">lhs</span></code> is processed.</p> <p><code class="docutils literal"><span class="pre">compiler</span></code> is an <code class="docutils literal"><span class="pre">SQLCompiler</span></code> object, to be used like <code class="docutils literal"><span class="pre">compiler.compile(lhs)</span></code> for compiling <code class="docutils literal"><span class="pre">lhs</span></code>. The <code class="docutils literal"><span class="pre">connection</span></code> can be used for compiling vendor specific SQL. If <code class="docutils literal"><span class="pre">lhs</span></code> is not <code class="docutils literal"><span class="pre">None</span></code>, use it as the processed <code class="docutils literal"><span class="pre">lhs</span></code> instead of <code class="docutils literal"><span class="pre">self.lhs</span></code>.</p> </dd></dl> <dl class="method"> <dt id="django.db.models.Lookup.process_rhs"> <code class="descname">process_rhs</code>(<em>compiler</em>, <em>connection</em>)<a class="reference internal" href="../../_modules/django/db/models/lookups.html#Lookup.process_rhs"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.Lookup.process_rhs" title="Permalink to this definition">¶</a></dt> <dd><p>Behaves the same way as <a class="reference internal" href="#django.db.models.Lookup.process_lhs" title="django.db.models.Lookup.process_lhs"><code class="xref py py-meth docutils literal"><span class="pre">process_lhs()</span></code></a>, for the right-hand side.</p> </dd></dl> </dd></dl> </div> </div> </div> </div> </div> <div class="yui-b" id="sidebar"> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">Lookup API reference</a><ul> <li><a class="reference internal" href="#registration-api">Registration API</a></li> <li><a class="reference internal" href="#the-query-expression-api">The Query Expression API</a></li> <li><a class="reference internal" href="#transform-reference">Transform reference</a></li> <li><a class="reference internal" href="#lookup-reference">Lookup reference</a></li> </ul> </li> </ul> <h3>Browse</h3> <ul> <li>Prev: <a href="querysets.html">QuerySet API reference</a></li> <li>Next: <a href="expressions.html">Query Expressions</a></li> </ul> <h3>You are here:</h3> <ul> <li> <a href="../../index.html">Django 1.8.19 documentation</a> <ul><li><a href="../index.html">API Reference</a> <ul><li><a href="index.html">Models</a> <ul><li>Lookup API reference</li></ul> </li></ul></li></ul> </li> </ul> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../../_sources/ref/models/lookups.txt" rel="nofollow">Show Source</a></li> </ul> </div> <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="querysets.html" title="QuerySet API reference">previous</a> | <a href="../index.html" title="API Reference" accesskey="U">up</a> | <a href="expressions.html" title="Query Expressions">next</a> »</div> </div> </div> <div class="clearer"></div> </div> </body> </html>