Azure Cosmos DB for MongoDB (vCore) operators

2025-06-04

This article contains details for various supported operators you can use with Azure Cosmos DB for MongoDB (vCore).

Aggregation

	Description
`$count`	The `$count` stage in the aggregation pipeline is used to count the number of documents that pass through the pipeline.
`$facet`	The `$facet` stage aggregation pipelines allow for multiple parallel aggregations to be executed within a single pipeline stage.
`$geonear`	The `$geoNear` aggregation stage calculates distances between a specified point and the location field in each document, sorts the documents by distance, and can optionally limit results by distance.
`$lookup`	The `$lookup` stage in the Aggregation Framework is used to perform left outer joins with other collections.
`$match`	The `$match` stage in the aggregation pipeline is used to filter documents that match a specified condition.

Array expression

	Description
`$arrayToObject`	The `$arrayToObject` operator is used to convert an array into a single document.
`$concatArrays`	The `$concatArrays` operator is used to combine multiple arrays into a single array.
`$filter`	The `$filter` operator is used to filter elements from an array based on a specified condition.
`$indexOfArray`	The `$indexOfArray` operator is used to search for an element in an array and return the index of the first occurrence of the element.
`$map`	The `$map` operator in MongoDB is used to apply an expression to each element in an array and return an array with the applied results.
`$reduce`	The `$reduce` operator is used to apply an expression to each element in an array and accumulate the results into a single value.
`$reverseArray`	The `$reverseArray` operator is used to reverse the order of elements in an array.
`$slice`	The `$slice` operator is used to return a subset of an array.
`$sortArray`	The `$sortArray` operator is used to sort the elements of an array.
`$zip`	The `$zip` operator is used to merge two or more arrays element-wise into a single array of arrays.

Array query

	Description
`$all`	The `$all` operator is used to select documents where the value of a field is an array that contains all the specified elements.
`$elemMatch`	The `$elemMatch` operator is used to match documents that contain an array field with at least one element that matches all the specified query criteria.
`$size`	The `$size` operator is used to query documents where an array field has a specified number of elements.

Array update

	Description
`$each`	The `$each` operator is used within an `$addToSet` or `$push` operation to add multiple elements to an array field in a single update operation.
`$positional`	The `$position` is used to specify the position in the array where a new element should be inserted.
`$pullAll`	The `$pullAll` operator removes all instances of the specified values from an existing array.
`$push`	The `$push` operator appends a specified value to an array.
`$slice`	The `$slice` operator limits the number of array elements that are returned or modified.
`$sort`	The `$sort` operator sorts the elements of an array.

Bitwise query

	Description
`$bitsAllClear`	The `$bitsAllClear` operator is used to match documents where all the bit positions specified in a bitmask are clear (that is, 0).
`$bitsAllSet`	The `$bitsAllSet` operator is used to match documents where all the bit positions specified in a bitmask are set (that is, 1).
`$bitsAnyClear`	The `$bitsAnyClear` operator is used to match documents where any bit positions specified in a bitmask are clear (that is, 0).
`$bitsAnySet`	The `$bitsAnySet` operator is used to match documents where any bit positions specified in a bitmask are set (that is, 1).

Comparison query

	Description
`$eq`	The `$eq` operator matches documents where the value of a field equals the specified value.

Data expression

	Description
`$dateadd`	The `$dateAdd` operator adds a specified number of time units to a date value.
`$datediff`	The `$dateDiff` operator returns the difference between two dates.
`$datefromparts`	The `$dateFromParts` operator constructs a date from the specified parts.
`$datefromstring`	The `$dateFromString` operator converts a date/time string to a date object.

Evaluation query

	Description
`$expr`	The `$expr` operator allows the use of aggregation expressions within the query language.

Geospatial

	Description
`$geoIntersect`	The `$geoIntersects` operator selects documents whose geospatial data intersects with a specified GeoJSON object.

Logical query

	Description
`$and`	The `$and` operator joins query clauses with a logical AND and returns all documents that match the conditions of both clauses.
`$nor`	The `$nor` operator performs a logical NOR operation on an array of one or more query expressions and selects the documents that fail all the query expressions in the array.
`$not`	The `$not` operator inverts the effect of a query expression and returns documents that don't match the query expression.
`$or`	The `$or` operator performs a logical OR operation on an array of two or more expressions and selects the documents that satisfy at least one of the expressions.

Object expression

	Description
`$mergeObjects`	The `$mergeObjects` operator combines multiple documents into a single document.
`$objectToArray`	The `$objectToArray` operator converts a document (object) into an array of key-value pairs.
`$setField`	The `$setField` operator sets or updates the value of a field in a document.

Projection

	Description
`$elemMatch`	The `$elemMatch` projection operator limits the contents of an array field from the query results to contain only those array elements that match the specified query condition.
`$meta`	The `$meta` projection operator returns metadata about the query, such as the text score.
`$slice`	The `$slice` projection operator limits the number of elements projected from an array field.