java.lang.Object
- com.mongodb.client.model.Aggregates

```
public final class Aggregates
extends Object
```
Builders for aggregation pipeline stages.

Since:

3.1

MongoDB documentation
Aggregation pipeline
Since server release
2.2

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static Bson`	`addFields(Field<?>... fields)`	Creates an $addFields pipeline stage
`static Bson`	`addFields(List<Field<?>> fields)`	Creates an $addFields pipeline stage
`static <TExpression,Boundary> Bson`	`bucket(TExpression groupBy, List<Boundary> boundaries)`	Creates a $bucket pipeline stage
`static <TExpression,TBoundary> Bson`	`bucket(TExpression groupBy, List<TBoundary> boundaries, BucketOptions options)`	Creates a $bucket pipeline stage
`static <TExpression> Bson`	`bucketAuto(TExpression groupBy, int buckets)`	Creates a $bucketAuto pipeline stage
`static <TExpression> Bson`	`bucketAuto(TExpression groupBy, int buckets, BucketAutoOptions options)`	Creates a $bucketAuto pipeline stage
`static Bson`	`count()`	Creates a $count pipeline stage using the field name "count" to store the result
`static Bson`	`count(String field)`	Creates a $count pipeline stage using the named field to store the result
`static Bson`	`facet(Facet... facets)`	Creates a facet pipeline stage
`static Bson`	`facet(List<Facet> facets)`	Creates a facet pipeline stage
`static <TExpression> Bson`	`graphLookup(String from, TExpression startWith, String connectFromField, String connectToField, String as)`	Creates a graphLookup pipeline stage for the specified filter
`static <TExpression> Bson`	`graphLookup(String from, TExpression startWith, String connectFromField, String connectToField, String as, GraphLookupOptions options)`	Creates a graphLookup pipeline stage for the specified filter
`static <TExpression> Bson`	`group(TExpression id, BsonField... fieldAccumulators)`	Creates a $group pipeline stage for the specified filter
`static <TExpression> Bson`	`group(TExpression id, List<BsonField> fieldAccumulators)`	Creates a $group pipeline stage for the specified filter
`static Bson`	`limit(int limit)`	Creates a $limit pipeline stage for the specified filter
`static Bson`	`lookup(String from, String localField, String foreignField, String as)`	Creates a $lookup pipeline stage, joining the current collection with the one specified in from using equality match between the local field and the foreign field
`static Bson`	`lookup(String from, List<? extends Bson> pipeline, String as)`	Creates a $lookup pipeline stage, joining the current collection with the one specified in from using the given pipeline
`static <TExpression> Bson`	`lookup(String from, List<Variable<TExpression>> let, List<? extends Bson> pipeline, String as)`	Creates a $lookup pipeline stage, joining the current collection with the one specified in from using the given pipeline
`static Bson`	`match(Bson filter)`	Creates a $match pipeline stage for the specified filter
`static Bson`	`merge(MongoNamespace namespace)`	Creates a $merge pipeline stage that merges into the specified namespace
`static Bson`	`merge(MongoNamespace namespace, MergeOptions options)`	Creates a $merge pipeline stage that merges into the specified namespace using the specified options.
`static Bson`	`merge(String collectionName)`	Creates a $merge pipeline stage that merges into the specified collection
`static Bson`	`merge(String collectionName, MergeOptions options)`	Creates a $merge pipeline stage that merges into the specified collection using the specified options.
`static Bson`	`out(String collectionName)`	Creates a $out pipeline stage that writes into the specified collection
`static Bson`	`out(String databaseName, String collectionName)`	Creates a $out pipeline stage that supports outputting to a different database.
`static Bson`	`out(Bson destination)`	Creates a $out pipeline stage that writes out to the specified destination
`static Bson`	`project(Bson projection)`	Creates a $project pipeline stage for the specified projection
`static <TExpression> Bson`	`replaceRoot(TExpression value)`	Creates a $replaceRoot pipeline stage
`static <TExpression> Bson`	`replaceWith(TExpression value)`	Creates a $replaceRoot pipeline stage
`static Bson`	`sample(int size)`	Creates a $sample pipeline stage with the specified sample size
`static Bson`	`set(Field<?>... fields)`	Creates a $set pipeline stage for the specified projection
`static Bson`	`set(List<Field<?>> fields)`	Creates a $set pipeline stage for the specified projection
`static <TExpression> Bson`	`setWindowFields(TExpression partitionBy, Bson sortBy, WindowedComputation... output)`	Creates a `$setWindowFields` pipeline stage, which allows using window operators.
`static <TExpression> Bson`	`setWindowFields(TExpression partitionBy, Bson sortBy, List<WindowedComputation> output)`	Creates a `$setWindowFields` pipeline stage, which allows using window operators.
`static Bson`	`skip(int skip)`	Creates a $skip pipeline stage
`static Bson`	`sort(Bson sort)`	Creates a $sort pipeline stage for the specified sort specification
`static <TExpression> Bson`	`sortByCount(TExpression filter)`	Creates a $sortByCount pipeline stage for the specified filter
`static Bson`	`unionWith(String collection, List<? extends Bson> pipeline)`	Creates a $unionWith pipeline stage.
`static Bson`	`unwind(String fieldName)`	Creates a $unwind pipeline stage for the specified field name, which must be prefixed by a `'$'` sign.
`static Bson`	`unwind(String fieldName, UnwindOptions unwindOptions)`	Creates a $unwind pipeline stage for the specified field name, which must be prefixed by a `'$'` sign.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - addFields
```
public static Bson addFields(Field<?>... fields)
```
    Creates an $addFields pipeline stage
    
    Parameters:
    
    fields - the fields to add
    
    Returns:
    
    the $addFields pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $addFields
    Since server release
    3.4
  - addFields
```
public static Bson addFields(List<Field<?>> fields)
```
    Creates an $addFields pipeline stage
    
    Parameters:
    
    fields - the fields to add
    
    Returns:
    
    the $addFields pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $addFields
    Since server release
    3.4
  - set
```
public static Bson set(Field<?>... fields)
```
    Creates a $set pipeline stage for the specified projection
    
    Parameters:
    
    fields - the fields to add
    
    Returns:
    
    the $set pipeline stage
    
    Since:
    
    4.3
    
    See Also:
    
    Projections
    
    MongoDB documentation
    $set
    Since server release
    4.2
  - set
```
public static Bson set(List<Field<?>> fields)
```
    Creates a $set pipeline stage for the specified projection
    
    Parameters:
    
    fields - the fields to add
    
    Returns:
    
    the $set pipeline stage
    
    Since:
    
    4.3
    
    See Also:
    
    Projections
    
    MongoDB documentation
    $set
    Since server release
    4.2
  - bucket
```
public static <TExpression,Boundary> Bson bucket(TExpression groupBy,
                                                       List<Boundary> boundaries)
```
    Creates a $bucket pipeline stage
    
    Type Parameters:
    
    TExpression - the groupBy expression type
    
    Boundary - the boundary type
    
    Parameters:
    
    groupBy - the criteria to group By
    
    boundaries - the boundaries of the buckets
    
    Returns:
    
    the $bucket pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $bucket
    Since server release
    3.4
  - bucket
```
public static <TExpression,TBoundary> Bson bucket(TExpression groupBy,
                                                        List<TBoundary> boundaries,
                                                        BucketOptions options)
```
    Creates a $bucket pipeline stage
    
    Type Parameters:
    
    TExpression - the groupBy expression type
    
    TBoundary - the boundary type
    
    Parameters:
    
    groupBy - the criteria to group By
    
    boundaries - the boundaries of the buckets
    
    options - the optional values for the $bucket stage
    
    Returns:
    
    the $bucket pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $bucket
    Since server release
    3.4
  - bucketAuto
```
public static <TExpression> Bson bucketAuto(TExpression groupBy,
                                            int buckets)
```
    Creates a $bucketAuto pipeline stage
    
    Type Parameters:
    
    TExpression - the groupBy expression type
    
    Parameters:
    
    groupBy - the criteria to group By
    
    buckets - the number of the buckets
    
    Returns:
    
    the $bucketAuto pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $bucketAuto
    Since server release
    3.4
  - bucketAuto
```
public static <TExpression> Bson bucketAuto(TExpression groupBy,
                                            int buckets,
                                            BucketAutoOptions options)
```
    Creates a $bucketAuto pipeline stage
    
    Type Parameters:
    
    TExpression - the groupBy expression type
    
    Parameters:
    
    groupBy - the criteria to group By
    
    buckets - the number of the buckets
    
    options - the optional values for the $bucketAuto stage
    
    Returns:
    
    the $bucketAuto pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $bucketAuto
    Since server release
    3.4
  - count
```
public static Bson count()
```
    Creates a $count pipeline stage using the field name "count" to store the result
    
    Returns:
    
    the $count pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $count
    Since server release
    3.4
  - count
```
public static Bson count(String field)
```
    Creates a $count pipeline stage using the named field to store the result
    
    Parameters:
    
    field - the field in which to store the count
    
    Returns:
    
    the $count pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $count
    Since server release
    3.4
  - match
```
public static Bson match(Bson filter)
```
    Creates a $match pipeline stage for the specified filter
    
    Parameters:
    
    filter - the filter to match
    
    Returns:
    
    the $match pipeline stage
    
    See Also:
    
    Filters
    
    MongoDB documentation
    $match
  - project
```
public static Bson project(Bson projection)
```
    Creates a $project pipeline stage for the specified projection
    
    Parameters:
    
    projection - the projection
    
    Returns:
    
    the $project pipeline stage
    
    See Also:
    
    Projections
    
    MongoDB documentation
    $project
  - sort
```
public static Bson sort(Bson sort)
```
    Creates a $sort pipeline stage for the specified sort specification
    
    Parameters:
    
    sort - the sort specification
    
    Returns:
    
    the $sort pipeline stage
    
    See Also:
    
    Sorts
    
    MongoDB documentation
    $sort
  - sortByCount
```
public static <TExpression> Bson sortByCount(TExpression filter)
```
    Creates a $sortByCount pipeline stage for the specified filter
    
    Type Parameters:
    
    TExpression - the expression type
    
    Parameters:
    
    filter - the filter specification
    
    Returns:
    
    the $sortByCount pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $sortByCount
    Since server release
    3.4
  - skip
```
public static Bson skip(int skip)
```
    Creates a $skip pipeline stage
    
    Parameters:
    
    skip - the number of documents to skip
    
    Returns:
    
    the $skip pipeline stage
    
    MongoDB documentation
    $skip
  - limit
```
public static Bson limit(int limit)
```
    Creates a $limit pipeline stage for the specified filter
    
    Parameters:
    
    limit - the limit
    
    Returns:
    
    the $limit pipeline stage
    
    MongoDB documentation
    $limit
  - lookup
```
public static Bson lookup(String from,
                          String localField,
                          String foreignField,
                          String as)
```
    Creates a $lookup pipeline stage, joining the current collection with the one specified in from using equality match between the local field and the foreign field
    
    Parameters:
    
    from - the name of the collection in the same database to perform the join with.
    
    localField - the field from the local collection to match values against.
    
    foreignField - the field in the from collection to match values against.
    
    as - the name of the new array field to add to the input documents.
    
    Returns:
    
    the $lookup pipeline stage
    
    Since:
    
    3.2
    
    MongoDB documentation
    $lookup
    Since server release
    3.2
  - lookup
```
public static Bson lookup(String from,
                          List<? extends Bson> pipeline,
                          String as)
```
    Creates a $lookup pipeline stage, joining the current collection with the one specified in from using the given pipeline
    
    Parameters:
    
    from - the name of the collection in the same database to perform the join with.
    
    pipeline - the pipeline to run on the joined collection.
    
    as - the name of the new array field to add to the input documents.
    
    Returns:
    
    the $lookup pipeline stage
    
    Since:
    
    3.7
    
    MongoDB documentation
    $lookup
    Since server release
    3.6
  - lookup
```
public static <TExpression> Bson lookup(String from,
                                        @Nullable
                                        List<Variable<TExpression>> let,
                                        List<? extends Bson> pipeline,
                                        String as)
```
    Creates a $lookup pipeline stage, joining the current collection with the one specified in from using the given pipeline
    
    Type Parameters:
    
    TExpression - the Variable value expression type
    
    Parameters:
    
    from - the name of the collection in the same database to perform the join with.
    
    let - the variables to use in the pipeline field stages.
    
    pipeline - the pipeline to run on the joined collection.
    
    as - the name of the new array field to add to the input documents.
    
    Returns:
    
    the $lookup pipeline stage
    
    Since:
    
    3.7
    
    MongoDB documentation
    $lookup
    Since server release
    3.6
  - facet
```
public static Bson facet(List<Facet> facets)
```
    Creates a facet pipeline stage
    
    Parameters:
    
    facets - the facets to use
    
    Returns:
    
    the new pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $facet
    Since server release
    3.4
  - facet
```
public static Bson facet(Facet... facets)
```
    Creates a facet pipeline stage
    
    Parameters:
    
    facets - the facets to use
    
    Returns:
    
    the new pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $facet
    Since server release
    3.4
  - graphLookup
```
public static <TExpression> Bson graphLookup(String from,
                                             TExpression startWith,
                                             String connectFromField,
                                             String connectToField,
                                             String as)
```
    Creates a graphLookup pipeline stage for the specified filter
    
    Type Parameters:
    
    TExpression - the expression type
    
    Parameters:
    
    from - the collection to query
    
    startWith - the expression to start the graph lookup with
    
    connectFromField - the from field
    
    connectToField - the to field
    
    as - name of field in output document
    
    Returns:
    
    the $graphLookup pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $graphLookup
    Since server release
    3.4
  - graphLookup
```
public static <TExpression> Bson graphLookup(String from,
                                             TExpression startWith,
                                             String connectFromField,
                                             String connectToField,
                                             String as,
                                             GraphLookupOptions options)
```
    Creates a graphLookup pipeline stage for the specified filter
    
    Type Parameters:
    
    TExpression - the expression type
    
    Parameters:
    
    from - the collection to query
    
    startWith - the expression to start the graph lookup with
    
    connectFromField - the from field
    
    connectToField - the to field
    
    as - name of field in output document
    
    options - optional values for the graphLookup
    
    Returns:
    
    the $graphLookup pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $graphLookup
    Since server release
    3.4
  - group
```
public static <TExpression> Bson group(@Nullable
                                       TExpression id,
                                       BsonField... fieldAccumulators)
```
    Creates a $group pipeline stage for the specified filter
    
    Type Parameters:
    
    TExpression - the expression type
    
    Parameters:
    
    id - the id expression for the group, which may be null
    
    fieldAccumulators - zero or more field accumulator pairs
    
    Returns:
    
    the $group pipeline stage
    
    MongoDB documentation
    $group
    Expressions
  - group
```
public static <TExpression> Bson group(@Nullable
                                       TExpression id,
                                       List<BsonField> fieldAccumulators)
```
    Creates a $group pipeline stage for the specified filter
    
    Type Parameters:
    
    TExpression - the expression type
    
    Parameters:
    
    id - the id expression for the group, which may be null
    
    fieldAccumulators - zero or more field accumulator pairs
    
    Returns:
    
    the $group pipeline stage
    
    MongoDB documentation
    $group
    Expressions
  - unionWith
```
public static Bson unionWith(String collection,
                             List<? extends Bson> pipeline)
```
    Creates a $unionWith pipeline stage.
    
    Parameters:
    
    collection - the name of the collection in the same database to perform the union with.
    
    pipeline - the pipeline to run on the union.
    
    Returns:
    
    the $unionWith pipeline stage
    
    Since:
    
    4.1
    
    MongoDB documentation
    $unionWith
    Since server release
    4.4
  - unwind
```
public static Bson unwind(String fieldName)
```
    Creates a $unwind pipeline stage for the specified field name, which must be prefixed by a '$' sign.
    
    Parameters:
    
    fieldName - the field name, prefixed by a '$' sign
    
    Returns:
    
    the $unwind pipeline stage
    
    MongoDB documentation
    $unwind
  - unwind
```
public static Bson unwind(String fieldName,
                          UnwindOptions unwindOptions)
```
    Creates a $unwind pipeline stage for the specified field name, which must be prefixed by a '$' sign.
    
    Parameters:
    
    fieldName - the field name, prefixed by a '$' sign
    
    unwindOptions - options for the unwind pipeline stage
    
    Returns:
    
    the $unwind pipeline stage
    
    Since:
    
    3.2
    
    MongoDB documentation
    $unwind
    Since server release
    3.2
  - out
```
public static Bson out(String collectionName)
```
    Creates a $out pipeline stage that writes into the specified collection
    
    Parameters:
    
    collectionName - the collection name
    
    Returns:
    
    the $out pipeline stage
    
    MongoDB documentation
    $out
  - out
```
public static Bson out(String databaseName,
                       String collectionName)
```
    Creates a $out pipeline stage that supports outputting to a different database.
    
    Parameters:
    
    databaseName - the database name
    
    collectionName - the collection name
    
    Returns:
    
    the $out pipeline stage
    
    Since:
    
    4.1
    
    MongoDB documentation
    $out
    Since server release
    4.4
  - out
```
public static Bson out(Bson destination)
```
    Creates a $out pipeline stage that writes out to the specified destination
    
    Parameters:
    
    destination - the destination details
    
    Returns:
    
    the $out pipeline stage
    
    Since:
    
    4.1
    
    MongoDB documentation
    $out
  - merge
```
public static Bson merge(String collectionName)
```
    Creates a $merge pipeline stage that merges into the specified collection
    
    Parameters:
    
    collectionName - the name of the collection to merge into
    
    Returns:
    
    the $merge pipeline stage
    
    Since:
    
    3.11
    
    MongoDB documentation
    $merge
    Since server release
    4.2
  - merge
```
public static Bson merge(MongoNamespace namespace)
```
    Creates a $merge pipeline stage that merges into the specified namespace
    
    Parameters:
    
    namespace - the namespace to merge into
    
    Returns:
    
    the $merge pipeline stage
    
    Since:
    
    3.11
    
    MongoDB documentation
    $merge
    Since server release
    4.2
  - merge
```
public static Bson merge(String collectionName,
                         MergeOptions options)
```
    Creates a $merge pipeline stage that merges into the specified collection using the specified options.
    
    Parameters:
    
    collectionName - the name of the collection to merge into
    
    options - the merge options
    
    Returns:
    
    the $merge pipeline stage
    
    Since:
    
    3.11
    
    MongoDB documentation
    $merge
    Since server release
    4.2
  - merge
```
public static Bson merge(MongoNamespace namespace,
                         MergeOptions options)
```
    Creates a $merge pipeline stage that merges into the specified namespace using the specified options.
    
    Parameters:
    
    namespace - the namespace to merge into
    
    options - the merge options
    
    Returns:
    
    the $merge pipeline stage
    
    Since:
    
    3.11
    
    MongoDB documentation
    $merge
    Since server release
    4.2
  - replaceRoot
```
public static <TExpression> Bson replaceRoot(TExpression value)
```
    Creates a $replaceRoot pipeline stage
    
    Type Parameters:
    
    TExpression - the new root type
    
    Parameters:
    
    value - the new root value
    
    Returns:
    
    the $replaceRoot pipeline stage
    
    Since:
    
    3.4
    
    MongoDB documentation
    $replaceRoot
    Since server release
    3.4
  - replaceWith
```
public static <TExpression> Bson replaceWith(TExpression value)
```
    Creates a $replaceRoot pipeline stage
    With $replaceWith, you can promote an embedded document to the top-level. You can also specify a new document as the replacement.
    
    The $replaceWith is an alias for replaceRoot(Object).
    
    Type Parameters:
    
    TExpression - the new root type
    
    Parameters:
    
    value - the new root value
    
    Returns:
    
    the $replaceRoot pipeline stage
    
    Since:
    
    3.11
    
    MongoDB documentation
    $replaceWith
    Since server release
    4.2
  - sample
```
public static Bson sample(int size)
```
    Creates a $sample pipeline stage with the specified sample size
    
    Parameters:
    
    size - the sample size
    
    Returns:
    
    the $sample pipeline stage
    
    Since:
    
    3.2
    
    MongoDB documentation
    $sample
    Since server release
    3.2
  - setWindowFields
```
@Beta
public static <TExpression> Bson setWindowFields(@Nullable
                                                 TExpression partitionBy,
                                                 @Nullable
                                                 Bson sortBy,
                                                 WindowedComputation... output)
```
    Creates a $setWindowFields pipeline stage, which allows using window operators. This stage partitions the input documents similarly to the $group pipeline stage, optionally sorts them, computes fields in the documents by computing window functions over windows specified per function, and outputs the documents. The important difference from the $group pipeline stage is that documents belonging to the same partition or window are not folded into a single document.
    
    Type Parameters:
    
    TExpression - The partitionBy expression type.
    
    Parameters:
    
    partitionBy - Optional partitioning of data specified like id in group(Object, List). If null, then all documents belong to the same partition.
    
    sortBy - Fields to sort by. The syntax is identical to sort in sort(Bson) (see Sorts). Sorting is required by certain functions and may be required by some windows (see Windows for more details). Sorting is used only for the purpose of computing window functions and does not guarantee ordering of the output documents.
    
    output - A nonempty array of windowed computations.
    
    Returns:
    
    The $setWindowFields pipeline stage.
    
    Since:
    
    4.3
    
    MongoDB documentation
    $setWindowFields
    Since server release
    5.0
  - setWindowFields
```
@Beta
public static <TExpression> Bson setWindowFields(@Nullable
                                                 TExpression partitionBy,
                                                 @Nullable
                                                 Bson sortBy,
                                                 List<WindowedComputation> output)
```
    Creates a $setWindowFields pipeline stage, which allows using window operators. This stage partitions the input documents similarly to the $group pipeline stage, optionally sorts them, computes fields in the documents by computing window functions over windows specified per function, and outputs the documents. The important difference from the $group pipeline stage is that documents belonging to the same partition or window are not folded into a single document.
    
    Type Parameters:
    
    TExpression - The partitionBy expression type.
    
    Parameters:
    
    partitionBy - Optional partitioning of data specified like id in group(Object, List). If null, then all documents belong to the same partition.
    
    sortBy - Fields to sort by. The syntax is identical to sort in sort(Bson) (see Sorts). Sorting is required by certain functions and may be required by some windows (see Windows for more details). Sorting is used only for the purpose of computing window functions and does not guarantee ordering of the output documents.
    
    output - A nonempty list of windowed computations.
    
    Returns:
    
    The $setWindowFields pipeline stage.
    
    Since:
    
    4.3
    
    MongoDB documentation
    $setWindowFields
    Since server release
    5.0

Class Aggregates

Method Summary

Methods inherited from class java.lang.Object

Method Detail

addFields

addFields

set

set

bucket

bucket

bucketAuto

bucketAuto

count

count

match

project

sort

sortByCount

skip

limit

lookup

lookup

lookup

facet

facet

graphLookup

graphLookup

group

group

unionWith

unwind

unwind

out

out

out

merge

merge

merge

merge

replaceRoot

replaceWith

sample

setWindowFields

setWindowFields