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CRUD & Aggregation APIs

Overview

This page lists MongoDB data source support for MongoDB commands, operators, options, and aggregation stages.

For information on how to read and write data in MongoDB from a function, see Query MongoDB Atlas.

For more information on supported features and limitations, see Service Limitations.

Note

Support for an operation may depend on whether you're running the operation as an application user or as a system user.

  • A user function runs in the context of a specific application user and enforces data access permissions and schema validation, which makes some operations untenable.

  • A system function runs as a generic system user and is not subject to rules or schema validation. Some operations are only available in system functions.

CRUD Operations

Query Operators

Atlas App Services supports most query operators for queries that run in a user function. However, some evaluation operators and all geospatial and bitwise operators are only available in system functions.

Comparison Operator Availability

Operation
User Function
System Function

$eq

Yes

Yes

$gt

Yes

Yes

$gte

Yes

Yes

$in

Yes

Yes

$lt

Yes

Yes

$lte

Yes

Yes

$ne

Yes

Yes

$nin

Yes

Yes

Logical Operator Availability

Operation
User Function
System Function

$and

Yes

Yes

$not

Yes

Yes

$nor

Yes

Yes

$or

Yes

Yes

Array Operator Availability

Operation
User Function
System Function

$all

Yes

Yes

$elemMatch

Yes

Yes

$size

Yes

Yes

Element Operator Availability

Operation
User Function
System Function

$exists

Yes

Yes

$type

Yes

Yes

Evaluation Operator Availability

Operation
User Function
System Function

$mod

Yes

Yes

$expr

No

Yes

$jsonSchema

No

Yes

$regex

No

Yes

$text

No

Yes

$where

No

Yes

Geospatial Operator Availability

Operation
User Function
System Function

$geoIntersects

No

Yes

$geoWithin

No

Yes

$near

No

Yes

$nearSphere

No

Yes

Bitwise Operator Availability

Operation
User Function
System Function

$bitsAllClear

No

Yes

$bitsAllSet

No

Yes

$bitsAnyClear

No

Yes

$bitsAnySet

No

Yes

Update Operators

App Services supports most update operators for queries that run in a user function. However, some array update operators are only available in system functions.

Field Update Operator Availability

Operation
User Function
System Function

$currentDate

Yes

Yes

$inc

Yes

Yes

$min

Yes

Yes

$max

Yes

Yes

$mul

Yes

Yes

$rename

Yes

Yes

$set

Yes

Yes

$setOnInsert

Yes

Yes

$unset

Yes

Yes

Array Update Operator Availability

Operation
User Function
System Function

$ (Positional Update)

Yes

Yes

$addToSet

Yes

Yes

$pop

Yes

Yes

$pull

Yes

Yes

$push

Yes

Yes

$pullAll

Yes

Yes

$[] (All Positional Update)

Yes

Yes

$[element] (Filtered Positional Update)

Yes

Yes

Array Update Operator Modifiers Availability

Modifier
User Function
System Function

$each

Yes

Yes

$position

Yes

Yes

$slice

Yes

Yes

$sort

Yes

Yes

Bitwise Update Operator Availability

Operator
User Function
System Function

$bit

Yes

Yes

Bulk Write Operations

App Services supports bulk write operations using the same API as the MongoDB Node.js driver.

Tip

App Services also provides the collection.bulkWrite() method for performing bulk write operations.

Ordered Bulk Write Operation Availability

You define ordered bulk operations by calling collection.initializeOrderedBulkOp() and manipulating the OrderedBulkOperation object that it returns.

App Services supports the following OrderedBulkOperation methods:

Operation
User Function
System Function

execute

Yes

Yes

find

Yes

Yes

insert

Yes

Yes

Unordered Bulk Write Operation Availability

You define unordered bulk operations by calling collection.initializeUnorderedBulkOp() and manipulating the OrderedBulkOperation object that it returns.

App Services supports the following UnorderedBulkOperation methods:

Operation
User Function
System Function

execute

Yes

Yes

find

Yes

Yes

insert

Yes

Yes

Query Options

App Services does not support configuring the following options for any CRUD operation in user functions. All query options are available in system functions.

Query Option Availability

Option
User Context
System Context

Read Isolation (Read Concern)

No

Yes

Write Acknowledgment (Write Concern)

No

Yes

Collation

No

Yes

Aggregation

Aggregation Methods

App Services supports aggregation on the both the database and collection level using the following commands:

Aggregation Pipeline Stage Availability

All aggregation pipeline stages stages are available to the system user except for $indexStats. However, App Services does not support the following aggregation pipeline stages when you run an aggregation pipeline in the context of an application user.

Operation
Notes

$collStats

$facet

$geoNear

$graphLookup

$indexStats

$lookup

$merge

$out


By default, $merge and $out route the entire aggregation operation to
the cluster's primary node. If you want to force these stages to respect your
configured cluster read preference, set the enforceReadPref option to
true.

$search


App Services performs $search operations as a system user and
enforces field-level rules on the returned search results. This means
that a user may search on a field for which they do not have read access.
In this case, the search is based on the specified field but no returned
documents include the field.

The $$SEARCH_META
aggregation variable is only available for functions that
run as system or if the first role on the
searched collection
has its apply_when and read expressions set to true.
If neither of these two scenarios apply, $$SEARCH_META is undefined
and the aggregation will fail.

$unionWith

Aggregation Pipeline Operator Availability

App Services supports all aggregation pipeline operators when you run an aggregation pipeline in the system user context.

App Services supports all pipeline operators in an application user context except for the following operators:

Database Commands

App Services does not support any database commands in the Client SDKs or Functions. You can, however, call a limited subset of database commands when connected to a MongoDB cluster over the App Services wire protocol.

The following database commands are partially supported over the wire protocol. Unsupported options for each command are listed below.

Note

App Services Apps cannot run commands on the admin database.

Database Command Availability

Command
Unsupported Options
App Services-Specific Options

find

  • hint

  • skip

  • batchSize

  • comment

  • maxScan

  • maxTimeMS

  • readConcern

  • max

  • min

  • returnKey

  • showRecordId

  • tailable

  • awaitData

  • oplogReplay

  • noCursorTimeout

  • allowPartialResults

  • collation

aggregate

  • distinct

  • explain

  • allowDiskUse [1]

  • readConcern

  • collation

  • bypassDocumentValidation

  • hint

  • comment

  • writeConcern

  • enforceReadPref

count

  • limit

  • skip

  • hint

  • readConcern

insert

  • writeConcern

  • bypassDocumentValidation

update

  • bypassDocumentValidation

  • collation

delete

  • collation

[1] App Services supports allowDiskUse when run in a Function or Trigger with system-level permissions.

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