Django and MongoDB Feature Compatibility

Overview

On this page, you can find information about supported and unsupported features in Django MongoDB Backend. You can also find features currently planned for future releases. We will prioritize these upcoming features based on user demand, and you can request support for a feature by creating a JIRA issue.

Performance Limitations

Django MongoDB Backend supports the following operations, but they might be less performant:

Operation	Performance Notes
`$expr` operations	Queries that use the `$expr` operator might run slowly, since this operator often cannot predict which index to use and performs a collection scan. Some `QuerySet` operations, such as queries that specify an `in` lookup, use `$expr` to evaluate the query results and experience degraded performance. We plan to address this performance issue in a post-GA release.
`$lookup` operations	Queries that use the `$lookup` operator might run slowly. To improve performance, we recommend that you use embedded models instead of the `$lookup` operator when possible. To learn more about how to reduce `$lookup` operations, see the Reduce $lookup Operations guide in the MongoDB Atlas documentation.

MongoDB Features

This section indicates whether Django MongoDB Backend supports various MongoDB features.

Index Support

MongoDB Feature	Current Support
Atlas Search indexes	Partially Supported. You can use Django MongoDB Backend to create basic Atlas Search indexes that specify an index name and the fields to index. All other index definition fields are unsupported. MongoDB does not support Atlas Search indexes on some data types. To view a list of unsupported types, see Data Type Limitations in the MongoDB Atlas documentation.
Atlas Vector Search indexes	Partially Supported. You can use Django MongoDB Backend to create basic Atlas Vector Search indexes that specify an index name, the fields to index, and a similarity function. All other index definition fields are unsupported.
Compound indexes	✓
Embedded document indexes	✓
Geospatial indexes	✓
Multikey indexes	✓
Partial indexes	✓
Single field indexes	✓
Unique indexes	✓
Updating embedded model indexes after model creation	Unsupported.
`EmbeddedModelArrayField` indexes	✓
`PolymorphicEmbeddedModelField` and `PolymorphicEmbeddedModelArrayField` indexes	Unsupported.

Data Type Support

Django MongoDB Backend currently supports all MongoDB data types not included in the following table. To view a full list of supported types, see the MongoDB BSON Fields section of the Create Models guide.

BSON Data Type	Current Support
`Object`	✓ You can use embedded models and polymorphic embedded models to represent objects. If you are using the `EmbeddedModelField` field, the following limitations apply: - Foreign key fields are not supported. - Arbitrary or untyped embedded model fields are not supported. You must derive all fields from an `EmbeddedModel` class.
`Regular Expression`	Unsupported. However, we plan to support this type in a post-GA release.

Query Support

MongoDB Feature	Current Support
Aggregation operations	Partially Supported. The Django MongoDB Backend does not include custom Django field lookups for the MongoDB aggregation framework, but you can use the raw_aggregate() method.
Atlas Search queries	✓
Delete operations	✓
Geospatial queries	✓ Use the raw_aggregate() method to run geospatial queries instead of the GIS QuerySet API.
Insert operations	✓
Read operations	✓
Update operations	✓
Vector Search queries	✓

Database and Collection Support

MongoDB Feature	Current Support
Asynchronous support	✓
Authentication	✓
Cached data storage	Unsupported. However, we plan to add support for this feature in a post-GA release.
Change Streams	Unsupported. However, we plan to add support for this feature in a post-GA release.
Client-side Field Level Encryption and Queryable Encryption	Unsupported. However, we plan to add support for this feature in a post-GA release.
Collection interaction	✓
Database interaction	✓
GridFS	Unsupported. However, we plan to add support for this feature in a post-GA release.
Multiple models for one collection	Unsupported.
Representing documents	✓ Use models to represent MongoDB documents.
Schema validation	Unsupported. However, we plan to add support for this feature in a post-GA release.
Timeseries data	✓
Transactions	✓ You can use Django MongoDB Backend's custom transactions API with the following limitations: - `QuerySet.union()` is not supported within a transaction. - Savepoints, or nested atomic blocks, are not supported. The outermost atomic block starts a transaction, and any subsequent atomic blocks have no effect. - Your MongoDB deployment must be a replica set or sharded cluster.

Django Features

This section indicates whether the Django MongoDB Backend supports various Django features.

Field Support

Django MongoDB Backend currently supports all Django fields not included in the following table. To view a full list of supported fields, see the Django Fields section of the Create Models guide.

Django Field Type	Current Support
`AutoField`	Unsupported. The `BigAutoField` and `SmallAutoField` types are also not supported. Instead, use `ObjectIdField`.
`CompositePrimaryKey`	Unsupported.
`DateTimeField`	✓ Microsecond granularity for `DateTimeField` values is not supported.
`DurationField`	✓ `DurationField` stores milliseconds rather than microseconds.
`ForeignKey`	Partially Supported. You can use this field type with the following limitations: When possible, you should use an `EmbeddedModelField` instead of a `ForeignKey` field to avoid using `$lookup` operations. An `EmbeddedModelField` emulates a MongoDB embedded document and performs better than a `ForeignKey` field. To learn more about how to reduce `$lookup` operations, see the Reduce $lookup Operations guide in the Atlas documentation. Performance of CASCADE deletes on a `ForeignKey` field is not as performant as using an `EmbeddedModelField`.
`GeneratedField`	Unsupported.
`JSONField`	Partially Supported. You can use this field type with the following limitations: Django MongoDB Backend cannot distinguish between a JSON and a SQL `null` value. Queries that use `Value(None, JSONField())` or the `isnull` lookup return both JSON and SQL `null` values. Some queries with `Q` objects, such as `Q(value__foo="bar")`, might not work as expected. Filtering for `None` values incorrectly returns objects in which a field does not exist.

Query Support

Django MongoDB Backend currently supports all Django QuerySet methods not included in the following table. To view the supported methods, see QuerySet API in the Django documentation.

Django `QuerySet` Feature	Current Support
`delete()`	✓ You cannot use this method to perform queries that span multiple collections.
`extra()`	Unsupported.
Pattern-matching lookups	✓ You can only use these lookups to query string fields. The pattern-matching lookups are `iexact`, `startswith`, `istartswith`, `endswith`, `iendswith`, `contains`, `icontains`, `regex`, and `iregex`
`prefetch_related()`	Unsupported.
`raw()`	Unsupported. However, you can use the `raw_aggregate()` method to run queries that use MongoDB's aggregation pipeline syntax.
`update()`	✓ You cannot use this method to perform queries that span multiple collections.

Database Function Support

Django MongoDB Backend currently supports all database functions not included in the following table. To view a full list of functions, see Database Functions in the Django documentation.

Django Function	Current Support
`Chr`	Unsupported.
`ExtractQuarter`	Unsupported.
`MD5`	Unsupported.
`Now`	Unsupported.
`Ord`	Unsupported.
`Pad`	Unsupported.
`Repeat`	Unsupported.
`Reverse`	Unsupported.
`Right`	Unsupported.
`SHA1`, `SHA224`, `SHA256`, `SHA384`, `SHA512`	Unsupported.
`Sign`	Unsupported.
`Trunc`	Partially Supported. The `tzinfo` parameter of the `TruncDate` and `TruncTime` database functions is not supported.

Contrib App Support

Django Feature	Current Support
Django Admin	✓
Django Authentication	✓
GeoDjango	Partially Supported. This web framework is supported with the following limitations: The GIS QuerySet API is not supported. MongoDB does not support any spatial reference system identifiers other than 4326. `RasterField` is not supported.

Forms Support

Django MongoDB Backend supports Django forms, but PolymorphicEmbeddedModelField and PolymorphicEmbeddedModelArrayField do not appear in forms.

Management Command Support

Django MongoDB Backend currently supports all management commands not included in the following table. To view a full list of commands, see Available commands in the Django documentation.

Django Command	Current Support
`createcachetable`	Unsupported.
`dumpdata`	Unsupported. However, we plan to add support for this feature in a post-GA release.
`inspectdb`	Unsupported. However, we plan to add support for this feature in a post-GA release.
`loaddata`	Unsupported. However, we plan to add support for this feature in a post-GA release.

Migration Support

Django Feature	Current Support
Creating, deleting, and updating indexes through migration commands	Partially Supported. You cannot update indexes on embedded model or array fields.
DDL Transactions	Unsupported.
`migrate --fake-initial` option	Unsupported.
Migrations for embedded models	Partially Supported. Migration commands do not detect changes to embedded model fields or embedded models referenced by a `PolymorphicEmbeddedModelField` or `PolymorphicEmbeddedModelArrayField`.

Third Party Library Support

Library	Current Support
Django-filter	Partially Supported. To learn more about the use cases and limitations of this library, see Django filter in the Django MongoDB CLI documentation.
Django Rest Framework	Partially Supported. To learn more about the use cases and limitations of this library, see Django rest framework in the Django MongoDB CLI documentation.
Django-allauth	Partially Supported. To learn more about the use cases and limitations of this library, see Django allauth in the Django MongoDB CLI documentation.
Django Debug Toolbar	Partially Supported. To learn more about the use cases and limitations of this library, see Django debug toolbar in the Django MongoDB CLI documentation.

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