Query and Projection Operators

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Note

For details on specific operator, including syntax and examples, click on the specific operator to go to its reference page.

Query Selectors

Comparison

For comparison of different BSON type values, see the specified BSON comparison order.

NameDescription
$eqMatches values that are equal to a specified value.
$gtMatches values that are greater than a specified value.
$gteMatches values that are greater than or equal to a specified value.
$inMatches any of the values specified in an array.
$ltMatches values that are less than a specified value.
$lteMatches values that are less than or equal to a specified value.
$neMatches all values that are not equal to a specified value.
$ninMatches none of the values specified in an array.

Logical

NameDescription
$andJoins query clauses with a logical AND returns all documents that match the conditions of both clauses.
$notInverts the effect of a query expression and returns documents that do not match the query expression.
$norJoins query clauses with a logical NOR returns all documents that fail to match both clauses.
$orJoins query clauses with a logical OR returns all documents that match the conditions of either clause.

Element

NameDescription
$existsMatches documents that have the specified field.
$typeSelects documents if a field is of the specified type.

Evaluation

NameDescription
$exprAllows use of aggregation expressions within the query language.
$jsonSchemaValidate documents against the given JSON Schema.
$modPerforms a modulo operation on the value of a field and selects documents with a specified result.
$regexSelects documents where values match a specified regular expression.
$textPerforms text search.
$whereMatches documents that satisfy a JavaScript expression.

Geospatial

NameDescription
$geoIntersectsSelects geometries that intersect with a GeoJSON geometry. The 2dsphere index supports $geoIntersects.
$geoWithinSelects geometries within a bounding GeoJSON geometry. The 2dsphere and 2d indexes support $geoWithin.
$nearReturns geospatial objects in proximity to a point. Requires a geospatial index. The 2dsphere and 2d indexes support $near.
$nearSphereReturns geospatial objects in proximity to a point on a sphere. Requires a geospatial index. The 2dsphere and 2d indexes support $nearSphere.

Array

NameDescription
$allMatches arrays that contain all elements specified in the query.
$elemMatchSelects documents if element in the array field matches all the specified $elemMatch conditions.
$sizeSelects documents if the array field is a specified size.

Bitwise

NameDescription
$bitsAllClearMatches numeric or binary values in which a set of bit positions all have a value of 0 .
$bitsAllSetMatches numeric or binary values in which a set of bit positions all have a value of 1 .
$bitsAnyClearMatches numeric or binary values in which any bit from a set of bit positions has a value of 0 .
$bitsAnySetMatches numeric or binary values in which any bit from a set of bit positions has a value of 1 .

Comments

NameDescription
$commentAdds a comment to a query predicate.

Projection Operators

NameDescription
$Projects the first element in an array that matches the query condition.
$elemMatchProjects the first element in an array that matches the specified $elemMatch condition.
$metaProjects the document’s score assigned during $text operation.
$sliceLimits the number of elements projected from an array. Supports skip and limit slices.