<!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>Database Functions — 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="Request and response objects" href="../request-response.html" /> <link rel="prev" title="Conditional Expressions" href="conditional-expressions.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="conditional-expressions.html" title="Conditional Expressions">previous</a> | <a href="../index.html" title="API Reference" accesskey="U">up</a> | <a href="../request-response.html" title="Request and response objects">next</a> »</div> </div> <div id="bd"> <div id="yui-main"> <div class="yui-b"> <div class="yui-g" id="ref-models-database-functions"> <div class="section" id="s-module-django.db.models.functions"> <span id="s-database-functions"></span><span id="module-django.db.models.functions"></span><span id="database-functions"></span><h1>Database Functions<a class="headerlink" href="#module-django.db.models.functions" title="Permalink to this headline">¶</a></h1> <div class="versionadded"> <span class="title">New in Django 1.8.</span> </div> <p>The classes documented below provide a way for users to use functions provided by the underlying database as annotations, aggregations, or filters in Django. Functions are also <a class="reference internal" href="expressions.html"><span class="doc">expressions</span></a>, so they can be used and combined with other expressions like <a class="reference internal" href="querysets.html#aggregation-functions"><span class="std std-ref">aggregate functions</span></a>.</p> <p>We’ll be using the following model in examples of each function:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">Author</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span> <span class="n">name</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">CharField</span><span class="p">(</span><span class="n">max_length</span><span class="o">=</span><span class="mi">50</span><span class="p">)</span> <span class="n">age</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">PositiveIntegerField</span><span class="p">(</span><span class="n">null</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">blank</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="n">alias</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">CharField</span><span class="p">(</span><span class="n">max_length</span><span class="o">=</span><span class="mi">50</span><span class="p">,</span> <span class="n">null</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">blank</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="n">goes_by</span> <span class="o">=</span> <span class="n">models</span><span class="o">.</span><span class="n">CharField</span><span class="p">(</span><span class="n">max_length</span><span class="o">=</span><span class="mi">50</span><span class="p">,</span> <span class="n">null</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">blank</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> </pre></div> </div> <p>We don’t usually recommend allowing <code class="docutils literal"><span class="pre">null=True</span></code> for <code class="docutils literal"><span class="pre">CharField</span></code> since this allows the field to have two “empty values”, but it’s important for the <code class="docutils literal"><span class="pre">Coalesce</span></code> example below.</p> <div class="section" id="s-coalesce"> <span id="coalesce"></span><h2>Coalesce<a class="headerlink" href="#coalesce" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.functions.Coalesce"> <em class="property">class </em><code class="descname">Coalesce</code>(<em>*expressions</em>, <em>**extra</em>)<a class="reference internal" href="../../_modules/django/db/models/functions.html#Coalesce"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.functions.Coalesce" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <p>Accepts a list of at least two field names or expressions and returns the first non-null value (note that an empty string is not considered a null value). Each argument must be of a similar type, so mixing text and numbers will result in a database error.</p> <p>Usage examples:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># Get a screen name from least to most public</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models</span> <span class="k">import</span> <span class="n">Sum</span><span class="p">,</span> <span class="n">Value</span> <span class="k">as</span> <span class="n">V</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.functions</span> <span class="k">import</span> <span class="n">Coalesce</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">,</span> <span class="n">goes_by</span><span class="o">=</span><span class="s1">'Maggie'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">author</span> <span class="o">=</span> <span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">annotate</span><span class="p">(</span> <span class="gp">... </span> <span class="n">screen_name</span><span class="o">=</span><span class="n">Coalesce</span><span class="p">(</span><span class="s1">'alias'</span><span class="p">,</span> <span class="s1">'goes_by'</span><span class="p">,</span> <span class="s1">'name'</span><span class="p">))</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">author</span><span class="o">.</span><span class="n">screen_name</span><span class="p">)</span> <span class="go">Maggie</span> <span class="gp">>>> </span><span class="c1"># Prevent an aggregate Sum() from returning None</span> <span class="gp">>>> </span><span class="n">aggregated</span> <span class="o">=</span> <span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">aggregate</span><span class="p">(</span> <span class="gp">... </span> <span class="n">combined_age</span><span class="o">=</span><span class="n">Coalesce</span><span class="p">(</span><span class="n">Sum</span><span class="p">(</span><span class="s1">'age'</span><span class="p">),</span> <span class="n">V</span><span class="p">(</span><span class="mi">0</span><span class="p">)),</span> <span class="gp">... </span> <span class="n">combined_age_default</span><span class="o">=</span><span class="n">Sum</span><span class="p">(</span><span class="s1">'age'</span><span class="p">))</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">aggregated</span><span class="p">[</span><span class="s1">'combined_age'</span><span class="p">])</span> <span class="go">0</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">aggregated</span><span class="p">[</span><span class="s1">'combined_age_default'</span><span class="p">])</span> <span class="go">None</span> </pre></div> </div> <div class="admonition warning"> <p class="first admonition-title">Warning</p> <p>A Python value passed to <code class="docutils literal"><span class="pre">Coalesce</span></code> on MySQL may be converted to an incorrect type unless explicitly cast to the correct database type:</p> <div class="last highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.expressions</span> <span class="k">import</span> <span class="n">RawSQL</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.utils</span> <span class="k">import</span> <span class="n">timezone</span> <span class="gp">>>> </span><span class="n">now</span> <span class="o">=</span> <span class="n">timezone</span><span class="o">.</span><span class="n">now</span><span class="p">()</span> <span class="gp">>>> </span><span class="n">now_sql</span> <span class="o">=</span> <span class="n">RawSQL</span><span class="p">(</span><span class="s2">"cast(</span><span class="si">%s</span><span class="s2"> as datetime)"</span><span class="p">,</span> <span class="p">(</span><span class="n">now</span><span class="p">,))</span> <span class="gp">>>> </span><span class="n">Coalesce</span><span class="p">(</span><span class="s1">'updated'</span><span class="p">,</span> <span class="n">now_sql</span><span class="p">)</span> </pre></div> </div> </div> </div> <div class="section" id="s-concat"> <span id="concat"></span><h2>Concat<a class="headerlink" href="#concat" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.functions.Concat"> <em class="property">class </em><code class="descname">Concat</code>(<em>*expressions</em>, <em>**extra</em>)<a class="reference internal" href="../../_modules/django/db/models/functions.html#Concat"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.functions.Concat" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <p>Accepts a list of at least two text fields or expressions and returns the concatenated text. Each argument must be of a text or char type. If you want to concatenate a <code class="docutils literal"><span class="pre">TextField()</span></code> with a <code class="docutils literal"><span class="pre">CharField()</span></code>, then be sure to tell Django that the <code class="docutils literal"><span class="pre">output_field</span></code> should be a <code class="docutils literal"><span class="pre">TextField()</span></code>. This is also required when concatenating a <code class="docutils literal"><span class="pre">Value</span></code> as in the example below.</p> <p>This function will never have a null result. On backends where a null argument results in the entire expression being null, Django will ensure that each null part is converted to an empty string first.</p> <p>Usage example:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># Get the display name as "name (goes_by)"</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models</span> <span class="k">import</span> <span class="n">CharField</span><span class="p">,</span> <span class="n">Value</span> <span class="k">as</span> <span class="n">V</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.functions</span> <span class="k">import</span> <span class="n">Concat</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">,</span> <span class="n">goes_by</span><span class="o">=</span><span class="s1">'Maggie'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">author</span> <span class="o">=</span> <span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">annotate</span><span class="p">(</span> <span class="gp">... </span> <span class="n">screen_name</span><span class="o">=</span><span class="n">Concat</span><span class="p">(</span><span class="s1">'name'</span><span class="p">,</span> <span class="n">V</span><span class="p">(</span><span class="s1">' ('</span><span class="p">),</span> <span class="s1">'goes_by'</span><span class="p">,</span> <span class="n">V</span><span class="p">(</span><span class="s1">')'</span><span class="p">),</span> <span class="gp">... </span> <span class="n">output_field</span><span class="o">=</span><span class="n">CharField</span><span class="p">()))</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">author</span><span class="o">.</span><span class="n">screen_name</span><span class="p">)</span> <span class="go">Margaret Smith (Maggie)</span> </pre></div> </div> </div> <div class="section" id="s-length"> <span id="length"></span><h2>Length<a class="headerlink" href="#length" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.functions.Length"> <em class="property">class </em><code class="descname">Length</code>(<em>expression</em>, <em>**extra</em>)<a class="reference internal" href="../../_modules/django/db/models/functions.html#Length"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.functions.Length" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <p>Accepts a single text field or expression and returns the number of characters the value has. If the expression is null, then the length will also be null.</p> <p>Usage example:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># Get the length of the name and goes_by fields</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.functions</span> <span class="k">import</span> <span class="n">Length</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">author</span> <span class="o">=</span> <span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">annotate</span><span class="p">(</span> <span class="gp">... </span> <span class="n">name_length</span><span class="o">=</span><span class="n">Length</span><span class="p">(</span><span class="s1">'name'</span><span class="p">),</span> <span class="gp">... </span> <span class="n">goes_by_length</span><span class="o">=</span><span class="n">Length</span><span class="p">(</span><span class="s1">'goes_by'</span><span class="p">))</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">author</span><span class="o">.</span><span class="n">name_length</span><span class="p">,</span> <span class="n">author</span><span class="o">.</span><span class="n">goes_by_length</span><span class="p">)</span> <span class="go">(14, None)</span> </pre></div> </div> </div> <div class="section" id="s-lower"> <span id="lower"></span><h2>Lower<a class="headerlink" href="#lower" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.functions.Lower"> <em class="property">class </em><code class="descname">Lower</code>(<em>expression</em>, <em>**extra</em>)<a class="reference internal" href="../../_modules/django/db/models/functions.html#Lower"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.functions.Lower" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <p>Accepts a single text field or expression and returns the lowercase representation.</p> <p>Usage example:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.functions</span> <span class="k">import</span> <span class="n">Lower</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">author</span> <span class="o">=</span> <span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">annotate</span><span class="p">(</span><span class="n">name_lower</span><span class="o">=</span><span class="n">Lower</span><span class="p">(</span><span class="s1">'name'</span><span class="p">))</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">author</span><span class="o">.</span><span class="n">name_lower</span><span class="p">)</span> <span class="go">margaret smith</span> </pre></div> </div> </div> <div class="section" id="s-substr"> <span id="substr"></span><h2>Substr<a class="headerlink" href="#substr" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.functions.Substr"> <em class="property">class </em><code class="descname">Substr</code>(<em>expression</em>, <em>pos</em>, <em>length=None</em>, <em>**extra</em>)<a class="reference internal" href="../../_modules/django/db/models/functions.html#Substr"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.functions.Substr" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <p>Returns a substring of length <code class="docutils literal"><span class="pre">length</span></code> from the field or expression starting at position <code class="docutils literal"><span class="pre">pos</span></code>. The position is 1-indexed, so the position must be greater than 0. If <code class="docutils literal"><span class="pre">length</span></code> is <code class="docutils literal"><span class="pre">None</span></code>, then the rest of the string will be returned.</p> <p>Usage example:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># Set the alias to the first 5 characters of the name as lowercase</span> <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.functions</span> <span class="k">import</span> <span class="n">Substr</span><span class="p">,</span> <span class="n">Lower</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">update</span><span class="p">(</span><span class="n">alias</span><span class="o">=</span><span class="n">Lower</span><span class="p">(</span><span class="n">Substr</span><span class="p">(</span><span class="s1">'name'</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">5</span><span class="p">)))</span> <span class="go">1</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">)</span><span class="o">.</span><span class="n">alias</span><span class="p">)</span> <span class="go">marga</span> </pre></div> </div> </div> <div class="section" id="s-upper"> <span id="upper"></span><h2>Upper<a class="headerlink" href="#upper" title="Permalink to this headline">¶</a></h2> <dl class="class"> <dt id="django.db.models.functions.Upper"> <em class="property">class </em><code class="descname">Upper</code>(<em>expression</em>, <em>**extra</em>)<a class="reference internal" href="../../_modules/django/db/models/functions.html#Upper"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#django.db.models.functions.Upper" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <p>Accepts a single text field or expression and returns the uppercase representation.</p> <p>Usage example:</p> <div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">django.db.models.functions</span> <span class="k">import</span> <span class="n">Upper</span> <span class="gp">>>> </span><span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Margaret Smith'</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">author</span> <span class="o">=</span> <span class="n">Author</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">annotate</span><span class="p">(</span><span class="n">name_upper</span><span class="o">=</span><span class="n">Upper</span><span class="p">(</span><span class="s1">'name'</span><span class="p">))</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">author</span><span class="o">.</span><span class="n">name_upper</span><span class="p">)</span> <span class="go">MARGARET SMITH</span> </pre></div> </div> </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="#">Database Functions</a><ul> <li><a class="reference internal" href="#coalesce">Coalesce</a></li> <li><a class="reference internal" href="#concat">Concat</a></li> <li><a class="reference internal" href="#length">Length</a></li> <li><a class="reference internal" href="#lower">Lower</a></li> <li><a class="reference internal" href="#substr">Substr</a></li> <li><a class="reference internal" href="#upper">Upper</a></li> </ul> </li> </ul> <h3>Browse</h3> <ul> <li>Prev: <a href="conditional-expressions.html">Conditional Expressions</a></li> <li>Next: <a href="../request-response.html">Request and response objects</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>Database Functions</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/database-functions.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="conditional-expressions.html" title="Conditional Expressions">previous</a> | <a href="../index.html" title="API Reference" accesskey="U">up</a> | <a href="../request-response.html" title="Request and response objects">next</a> »</div> </div> </div> <div class="clearer"></div> </div> </body> </html>