Package com.mongodb

Class GroupCommand

java.lang.Object

com.mongodb.GroupCommand

public class GroupCommand
extends Object

This class groups the argument for a group operation and can build the underlying command object

MongoDB documentation

Group

Constructor Summary

Constructors

Constructor	Description
GroupCommand(DBCollection collection, DBObject keys, DBObject condition, DBObject initial, String reduce, String finalize)	Creates a new group command.
GroupCommand(DBCollection collection, DBObject keys, DBObject condition, DBObject initial, String reduce, String finalize, Collation collation)	Creates a new group command.
GroupCommand(DBCollection collection, String keyf, DBObject condition, DBObject initial, String reduce, String finalize)	Creates a new group command.
GroupCommand(DBCollection collection, String keyf, DBObject condition, DBObject initial, String reduce, String finalize, Collation collation)	Creates a new group command.

Method Summary

Modifier and Type	Method	Description
DBObject	toDBObject()	Turns this group command into the DBObject format of the command.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GroupCommand

public GroupCommand(DBCollection collection,
                    DBObject keys,
                    DBObject condition,
                    DBObject initial,
                    String reduce,
                    @Nullable
                    String finalize)

Creates a new group command.

Parameters:

collection - the collection from which to perform the group by operation.

keys - the field or fields to group.

condition - optional - a filter to determine which documents in the collection to process.

initial - the initial state of the aggregation result document.

reduce - a JavaScript aggregation function that operates on the documents during the grouping operation.

finalize - optional - a JavaScript function that runs each item in the result set before group returns the final value.

GroupCommand

public GroupCommand(DBCollection collection,
                    DBObject keys,
                    DBObject condition,
                    DBObject initial,
                    String reduce,
                    @Nullable
                    String finalize,
                    @Nullable
                    Collation collation)

Creates a new group command.

Parameters:

collection - the collection from which to perform the group by operation.

keys - the field or fields to group.

condition - optional - a filter to determine which documents in the collection to process.

initial - the initial state of the aggregation result document.

reduce - a JavaScript aggregation function that operates on the documents during the grouping operation.

finalize - optional - a JavaScript function that runs each item in the result set before group returns the final value.

collation - optional - the collation options

Since:

3.4

GroupCommand

public GroupCommand(DBCollection collection,
                    String keyf,
                    DBObject condition,
                    DBObject initial,
                    String reduce,
                    String finalize)

Creates a new group command.

Parameters:

collection - the collection from which to perform the group by operation.

keyf - the function that creates a "key object" for use as the grouping key

condition - optional - a filter to determine which documents in the collection to process.

initial - the initial state of the aggregation result document.

reduce - a JavaScript aggregation function that operates on the documents during the grouping operation.

finalize - optional - a JavaScript function that runs each item in the result set before group returns the final value.

Since:

3.1

GroupCommand

public GroupCommand(DBCollection collection,
                    String keyf,
                    DBObject condition,
                    DBObject initial,
                    String reduce,
                    @Nullable
                    String finalize,
                    @Nullable
                    Collation collation)

Creates a new group command.

Parameters:

collection - the collection from which to perform the group by operation.

keyf - the function that creates a "key object" for use as the grouping key

condition - optional - a filter to determine which documents in the collection to process.

initial - the initial state of the aggregation result document.

reduce - a JavaScript aggregation function that operates on the documents during the grouping operation.

finalize - optional - a JavaScript function that runs each item in the result set before group returns the final value.

collation - optional - the collation options

Since:

3.4

Method Detail

toDBObject

public DBObject toDBObject()

Turns this group command into the DBObject format of the command.

Returns:

a DBObject containing the group command as a MongoDB document