orbit-oss/flask
4
4
Fork 2
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
flask/flask-docs/patterns/mongoengine.html
pre-commit-ci-lite[bot] 261d7d1cca
[pre-commit.ci lite] apply automatic fixes
2025-04-10 22:13:49 +00:00

197 lines
14 KiB
HTML
Raw Blame History

<!DOCTYPE html>
<html lang="en" data-content_root="../">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>MongoDB with MongoEngine &#8212; Flask Documentation (3.2.x)</title>
<link rel="stylesheet" type="text/css" href="../_static/pygments.css?v=6625fa76" />
<link rel="stylesheet" type="text/css" href="../_static/flask.css?v=b87c8d14" />
<script src="../_static/documentation_options.js?v=56528222"></script>
<script src="../_static/doctools.js?v=9bcbadda"></script>
<script src="../_static/sphinx_highlight.js?v=dc90522c"></script>
<script data-project="flask" data-version="3.2.x" src="../_static/describe_version.js?v=fa7f30d0"></script>
<link rel="icon" href="../_static/shortcut-icon.png"/>
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<link rel="next" title="Adding a favicon" href="favicon.html" />
<link rel="prev" title="Lazily Loading Views" href="lazyloading.html" />
</head><body>
<div class="related" role="navigation" aria-label="Related">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="../py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="favicon.html" title="Adding a favicon"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="lazyloading.html" title="Lazily Loading Views"
accesskey="P">previous</a> |</li>
<li class="nav-item nav-item-0"><a href="../index.html">Flask Documentation (3.2.x)</a> &#187;</li>
<li class="nav-item nav-item-1"><a href="index.html" accesskey="U">Patterns for Flask</a> &#187;</li>
<li class="nav-item nav-item-this"><a href="">MongoDB with MongoEngine</a></li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<section id="mongodb-with-mongoengine">
<h1>MongoDB with MongoEngine<a class="headerlink" href="#mongodb-with-mongoengine" title="Link to this heading"></a></h1>
<p>Using a document database like MongoDB is a common alternative to
relational SQL databases. This pattern shows how to use
<a class="reference external" href="http://mongoengine.org">MongoEngine</a>, a document mapper library, to integrate with MongoDB.</p>
<p>A running MongoDB server and <a class="reference external" href="https://flask-mongoengine.readthedocs.io">Flask-MongoEngine</a> are required.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">pip</span> <span class="n">install</span> <span class="n">flask</span><span class="o">-</span><span class="n">mongoengine</span>
</pre></div>
</div>
<section id="configuration">
<h2>Configuration<a class="headerlink" href="#configuration" title="Link to this heading"></a></h2>
<p>Basic setup can be done by defining <code class="docutils literal notranslate"><span class="pre">MONGODB_SETTINGS</span></code> on
<code class="docutils literal notranslate"><span class="pre">app.config</span></code> and creating a <code class="docutils literal notranslate"><span class="pre">MongoEngine</span></code> instance.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">flask</span><span class="w"> </span><span class="kn">import</span> <span class="n">Flask</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">flask_mongoengine</span><span class="w"> </span><span class="kn">import</span> <span class="n">MongoEngine</span>
<span class="n">app</span> <span class="o">=</span> <span class="n">Flask</span><span class="p">(</span><span class="vm">__name__</span><span class="p">)</span>
<span class="n">app</span><span class="o">.</span><span class="n">config</span><span class="p">[</span><span class="s1">&#39;MONGODB_SETTINGS&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;db&quot;</span><span class="p">:</span> <span class="s2">&quot;myapp&quot;</span><span class="p">,</span>
<span class="p">}</span>
<span class="n">db</span> <span class="o">=</span> <span class="n">MongoEngine</span><span class="p">(</span><span class="n">app</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="mapping-documents">
<h2>Mapping Documents<a class="headerlink" href="#mapping-documents" title="Link to this heading"></a></h2>
<p>To declare a model that represents a Mongo document, create a class that
inherits from <code class="docutils literal notranslate"><span class="pre">Document</span></code> and declare each of the fields.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">mongoengine</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="nn">me</span>
<span class="k">class</span><span class="w"> </span><span class="nc">Movie</span><span class="p">(</span><span class="n">me</span><span class="o">.</span><span class="n">Document</span><span class="p">):</span>
<span class="n">title</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">StringField</span><span class="p">(</span><span class="n">required</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="n">year</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">IntField</span><span class="p">()</span>
<span class="n">rated</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">StringField</span><span class="p">()</span>
<span class="n">director</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">StringField</span><span class="p">()</span>
<span class="n">actors</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">ListField</span><span class="p">()</span>
</pre></div>
</div>
<p>If the document has nested fields, use <code class="docutils literal notranslate"><span class="pre">EmbeddedDocument</span></code> to
defined the fields of the embedded document and
<code class="docutils literal notranslate"><span class="pre">EmbeddedDocumentField</span></code> to declare it on the parent document.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="k">class</span><span class="w"> </span><span class="nc">Imdb</span><span class="p">(</span><span class="n">me</span><span class="o">.</span><span class="n">EmbeddedDocument</span><span class="p">):</span>
<span class="n">imdb_id</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">StringField</span><span class="p">()</span>
<span class="n">rating</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">DecimalField</span><span class="p">()</span>
<span class="n">votes</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">IntField</span><span class="p">()</span>
<span class="k">class</span><span class="w"> </span><span class="nc">Movie</span><span class="p">(</span><span class="n">me</span><span class="o">.</span><span class="n">Document</span><span class="p">):</span>
<span class="o">...</span>
<span class="n">imdb</span> <span class="o">=</span> <span class="n">me</span><span class="o">.</span><span class="n">EmbeddedDocumentField</span><span class="p">(</span><span class="n">Imdb</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="creating-data">
<h2>Creating Data<a class="headerlink" href="#creating-data" title="Link to this heading"></a></h2>
<p>Instantiate your document class with keyword arguments for the fields.
You can also assign values to the field attributes after instantiation.
Then call <code class="docutils literal notranslate"><span class="pre">doc.save()</span></code>.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">bttf</span> <span class="o">=</span> <span class="n">Movie</span><span class="p">(</span><span class="n">title</span><span class="o">=</span><span class="s2">&quot;Back To The Future&quot;</span><span class="p">,</span> <span class="n">year</span><span class="o">=</span><span class="mi">1985</span><span class="p">)</span>
<span class="n">bttf</span><span class="o">.</span><span class="n">actors</span> <span class="o">=</span> <span class="p">[</span>
<span class="s2">&quot;Michael J. Fox&quot;</span><span class="p">,</span>
<span class="s2">&quot;Christopher Lloyd&quot;</span>
<span class="p">]</span>
<span class="n">bttf</span><span class="o">.</span><span class="n">imdb</span> <span class="o">=</span> <span class="n">Imdb</span><span class="p">(</span><span class="n">imdb_id</span><span class="o">=</span><span class="s2">&quot;tt0088763&quot;</span><span class="p">,</span> <span class="n">rating</span><span class="o">=</span><span class="mf">8.5</span><span class="p">)</span>
<span class="n">bttf</span><span class="o">.</span><span class="n">save</span><span class="p">()</span>
</pre></div>
</div>
</section>
<section id="queries">
<h2>Queries<a class="headerlink" href="#queries" title="Link to this heading"></a></h2>
<p>Use the class <code class="docutils literal notranslate"><span class="pre">objects</span></code> attribute to make queries. A keyword argument
looks for an equal value on the field.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">bttf</span> <span class="o">=</span> <span class="n">Movie</span><span class="o">.</span><span class="n">objects</span><span class="p">(</span><span class="n">title</span><span class="o">=</span><span class="s2">&quot;Back To The Future&quot;</span><span class="p">)</span><span class="o">.</span><span class="n">get_or_404</span><span class="p">()</span>
</pre></div>
</div>
<p>Query operators may be used by concatenating them with the field name
using a double-underscore. <code class="docutils literal notranslate"><span class="pre">objects</span></code>, and queries returned by
calling it, are iterable.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">some_theron_movie</span> <span class="o">=</span> <span class="n">Movie</span><span class="o">.</span><span class="n">objects</span><span class="p">(</span><span class="n">actors__in</span><span class="o">=</span><span class="p">[</span><span class="s2">&quot;Charlize Theron&quot;</span><span class="p">])</span><span class="o">.</span><span class="n">first</span><span class="p">()</span>
<span class="k">for</span> <span class="n">recents</span> <span class="ow">in</span> <span class="n">Movie</span><span class="o">.</span><span class="n">objects</span><span class="p">(</span><span class="n">year__gte</span><span class="o">=</span><span class="mi">2017</span><span class="p">):</span>
<span class="nb">print</span><span class="p">(</span><span class="n">recents</span><span class="o">.</span><span class="n">title</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="documentation">
<h2>Documentation<a class="headerlink" href="#documentation" title="Link to this heading"></a></h2>
<p>There are many more ways to define and query documents with MongoEngine.
For more information, check out the <a class="reference external" href="http://mongoengine.org">official documentation</a>.</p>
<p>Flask-MongoEngine adds helpful utilities on top of MongoEngine. Check
out their <a class="reference external" href="https://flask-mongoengine.readthedocs.io">documentation</a> as well.</p>
</section>
</section>
<div class="clearer"></div>
</div>
</div>
</div>
<span id="sidebar-top"></span>
<div class="sphinxsidebar" role="navigation" aria-label="Main">
<div class="sphinxsidebarwrapper">
<p class="logo"><a href="../index.html">
<img class="logo" src="../_static/flask-vertical.png" alt="Logo of Flask"/>
</a></p>
<h3>Contents</h3>
<ul>
<li><a class="reference internal" href="#">MongoDB with MongoEngine</a><ul>
<li><a class="reference internal" href="#configuration">Configuration</a></li>
<li><a class="reference internal" href="#mapping-documents">Mapping Documents</a></li>
<li><a class="reference internal" href="#creating-data">Creating Data</a></li>
<li><a class="reference internal" href="#queries">Queries</a></li>
<li><a class="reference internal" href="#documentation">Documentation</a></li>
</ul>
</li>
</ul>
<h3>Navigation</h3>
<ul>
<li><a href="../index.html">Overview</a>
<ul>
<li><a href="index.html">Patterns for Flask</a>
<ul>
<li>Previous: <a href="lazyloading.html" title="previous chapter">Lazily Loading Views</a>
<li>Next: <a href="favicon.html" title="next chapter">Adding a favicon</a></ul>
</li>
</ul>
</li>
</ul>
<search id="searchbox" style="display: none" role="search">
<h3 id="searchlabel">Quick search</h3>
<div class="searchformwrapper">
<form class="search" action="../search.html" method="get">
<input type="text" name="q" aria-labelledby="searchlabel" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"/>
<input type="submit" value="Go" />
</form>
</div>
</search>
<script>document.getElementById('searchbox').style.display = "block"</script><div id="ethical-ad-placement"></div>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="footer" role="contentinfo">
&#169; Copyright 2010 Pallets.
Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 8.1.3.
</div>
</body>
</html>
Reference in a new issue View git blame Copy permalink