2025-04-10 15:52:02 -06:00
<!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" >
2025-04-11 03:04:22 +00:00
< title > MongoDB with MongoEngine — Flask Documentation (3.2.x)< / title >
2025-04-10 15:52:02 -06:00
< 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" / >
2025-04-11 03:04:22 +00:00
< 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" / >
2025-04-10 15:52:02 -06:00
< / 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 >
2025-04-11 03:04:22 +00:00
< 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 >
2025-04-10 15:52:02 -06:00
< li class = "nav-item nav-item-0" > < a href = "../index.html" > Flask Documentation (3.2.x)< / a > » < / li >
2025-04-11 03:04:22 +00:00
< li class = "nav-item nav-item-1" > < a href = "index.html" accesskey = "U" > Patterns for Flask< / a > » < / li >
< li class = "nav-item nav-item-this" > < a href = "" > MongoDB with MongoEngine< / a > < / li >
2025-04-10 15:52:02 -06:00
< / ul >
2025-04-11 03:04:22 +00:00
< / div >
2025-04-10 15:52:02 -06:00
< div class = "document" >
< div class = "documentwrapper" >
< div class = "bodywrapper" >
< div class = "body" role = "main" >
2025-04-11 03:04:22 +00:00
< 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" > ' MONGODB_SETTINGS' < / span > < span class = "p" > ]< / span > < span class = "o" > =< / span > < span class = "p" > {< / span >
< span class = "s2" > " db" < / span > < span class = "p" > :< / span > < span class = "s2" > " myapp" < / 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" > " Back To The Future" < / 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" > " Michael J. Fox" < / span > < span class = "p" > ,< / span >
< span class = "s2" > " Christopher Lloyd" < / 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" > " tt0088763" < / 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" > " Back To The Future" < / 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" > " Charlize Theron" < / 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 >
2025-04-10 15:52:02 -06:00
< / section >
< div class = "clearer" > < / div >
< / div >
< / div >
< / div >
< span id = "sidebar-top" > < / span >
< div class = "sphinxsidebar" role = "navigation" aria-label = "Main" >
< div class = "sphinxsidebarwrapper" >
2025-04-11 03:04:22 +00:00
2025-04-10 15:52:02 -06:00
< p class = "logo" > < a href = "../index.html" >
< img class = "logo" src = "../_static/flask-vertical.png" alt = "Logo of Flask" / >
< / a > < / p >
2025-04-11 03:04:22 +00:00
< 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 >
2025-04-10 15:52:02 -06:00
< h3 > Navigation< / h3 >
< ul >
< li > < a href = "../index.html" > Overview< / a >
2025-04-11 03:04:22 +00:00
< 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 >
2025-04-10 15:52:02 -06:00
< / 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" >
© Copyright 2010 Pallets.
Created using < a href = "https://www.sphinx-doc.org/" > Sphinx< / a > 8.1.3.
< / div >
< / body >
2025-04-11 03:04:22 +00:00
< / html >
