org.springframework.data.mongodb.core.mapreduce

Class GroupBy

java.lang.Object

org.springframework.data.mongodb.core.mapreduce.GroupBy

public class GroupBy
extends Object

Collects the parameters required to perform a group operation on a collection. The query condition and the input collection are specified on the group method as method arguments to be consistent with other operations, e.g. map-reduce.

Author:

Mark Pollack, Christoph Strobl, Mark Paluch

Constructor Summary

Constructors

Constructor and Description
GroupBy(String... keys)
GroupBy(String key, boolean isKeyFunction)

Method Summary

Modifier and Type	Method and Description
GroupBy	collation(Collation collation) Define the Collation specifying language-specific rules for string comparison.
GroupBy	finalizeFunction(String finalizeFunction) Define the function that runs each item in the result set before db.collection.group() returns the final value.
org.bson.Document	getGroupByObject() Get the Document representation of the GroupBy.
GroupBy	initialDocument(org.bson.Document initialDocument) Define the aggregation result document.
GroupBy	initialDocument(String initialDocument) Define the aggregation result document.
static GroupBy	key(String... keys) Create new GroupBy with the fields to group.
static GroupBy	keyFunction(String key) Create new GroupBy with the field to group.
GroupBy	reduceFunction(String reduceFunction) Define the aggregation function that operates on the documents during the grouping operation

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupBy

public GroupBy(String... keys)

GroupBy

public GroupBy(@Nullable
               String key,
               boolean isKeyFunction)

Method Detail

keyFunction

public static GroupBy keyFunction(String key)

Create new GroupBy with the field to group.

Parameters:

key -

Returns:

key

public static GroupBy key(String... keys)

Create new GroupBy with the fields to group.

Parameters:

keys -

Returns:

initialDocument

public GroupBy initialDocument(@Nullable
                               String initialDocument)

Define the aggregation result document.

Parameters:

initialDocument - can be null.

Returns:

initialDocument

public GroupBy initialDocument(@Nullable
                               org.bson.Document initialDocument)

Define the aggregation result document.

Parameters:

initialDocument - can be null.

Returns:

reduceFunction

public GroupBy reduceFunction(String reduceFunction)

Define the aggregation function that operates on the documents during the grouping operation

Parameters:

reduceFunction -

Returns:

finalizeFunction

public GroupBy finalizeFunction(@Nullable
                                String finalizeFunction)

Define the function that runs each item in the result set before db.collection.group() returns the final value.

Parameters:

finalizeFunction -

Returns:

collation

public GroupBy collation(@Nullable
                         Collation collation)

Define the Collation specifying language-specific rules for string comparison.

Parameters:

collation - can be null.

Returns:

Since:

2.0

getGroupByObject

public org.bson.Document getGroupByObject()

Get the Document representation of the GroupBy.

Returns: