Package dev.morphia.aggregation.stages

Class Merge<M>

java.lang.Object

dev.morphia.aggregation.stages.Stage

dev.morphia.aggregation.stages.Merge<M>

Type Parameters:

M - the entity type

public class Merge<M>
extends Stage

Writes the results of the aggregation pipeline to a specified collection. The $merge operator must be the last stage in the pipeline.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Merge()
protected	Merge(Class<M> type)
protected	Merge(String collection)
protected	Merge(String database, String collection)

Method Summary

Modifier and Type	Method	Description
String	getCollection()
String	getDatabase()
List<String>	getOn()
Class<M>	getType()
Map<String,Expression>	getVariables()
MergeOptions.WhenMatched	getWhenMatched()
List<Stage>	getWhenMatchedPipeline()
MergeOptions.WhenNotMatched	getWhenNotMatched()
static <M> Merge<M>	into(Class<M> type)	Creates a new stage targeting the collection mapped for the given type
static Merge<?>	into(String collection)	Creates a new stage targeting the collection
static Merge<?>	into(String database, String collection)	Creates a new stage targeting the database and collection
Merge<M>	let(String variable, Expression value)	Specifies a variable accessible for use in the whenMatched pipeline
Merge<M>	on(String field, String... fields)	Optional.
Merge<M>	whenMatched(MergeOptions.WhenMatched whenMatched)	Optional.
Merge<M>	whenMatched(List<Stage> pipeline)	Optional.
Merge<M>	whenNotMatched(MergeOptions.WhenNotMatched whenNotMatched)	Optional.

Methods inherited from class dev.morphia.aggregation.stages.Stage

aggregation, stageName

Methods inherited from class java.lang.Object

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

Constructor Detail

Merge

protected Merge(Class<M> type)

Merge

protected Merge()

Merge

protected Merge(String collection)

Merge

protected Merge(String database,
                String collection)

Method Detail

into

public static <M> Merge<M> into(Class<M> type)

Creates a new stage targeting the collection mapped for the given type

Type Parameters:

M - the entity type

Parameters:

type - the target type

Returns:

the new stage

into

public static Merge<?> into(String collection)

Creates a new stage targeting the collection

Parameters:

collection - the target collection

Returns:

the new stage

into

public static Merge<?> into(String database,
                            String collection)

Creates a new stage targeting the database and collection

Parameters:

database - the target database

collection - the target collection

Returns:

the new stage

getCollection

@MorphiaInternal
public String getCollection()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getDatabase

@Nullable
@MorphiaInternal
public String getDatabase()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getOn

@MorphiaInternal
public List<String> getOn()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getType

@Nullable
@MorphiaInternal
public Class<M> getType()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getVariables

@MorphiaInternal
public Map<String,Expression> getVariables()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getWhenMatched

@MorphiaInternal
public MergeOptions.WhenMatched getWhenMatched()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getWhenMatchedPipeline

@MorphiaInternal
public List<Stage> getWhenMatchedPipeline()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

getWhenNotMatched

@MorphiaInternal
public MergeOptions.WhenNotMatched getWhenNotMatched()

Returns:

the value

Developer note.

This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

let

public Merge<M> let(String variable,
                    Expression value)

Specifies a variable accessible for use in the whenMatched pipeline

Parameters:

variable - the variable name

value - the value expression

Returns:

this

on

public Merge<M> on(String field,
                   String... fields)

Optional. Field or fields that act as a unique identifier for a document. The identifier determines if a results document matches an already existing document in the output collection.

Parameters:

field - the first field

fields - the other fields

Returns:

this

whenMatched

public Merge<M> whenMatched(MergeOptions.WhenMatched whenMatched)

Optional. The behavior of $merge if a result document and an existing document in the collection have the same value for the specified on field(s).

Parameters:

whenMatched - the behavior

Returns:

this

whenMatched

public Merge<M> whenMatched(List<Stage> pipeline)

Optional. An aggregation pipeline to update the document in the collection.

Parameters:

pipeline - the pipeline

Returns:

this

whenNotMatched

public Merge<M> whenNotMatched(MergeOptions.WhenNotMatched whenNotMatched)

Optional. The behavior of $merge if a result document does not match an existing document in the out collection.

Parameters:

whenNotMatched - the behavior

Returns:

this