Module spring.data.mongodb

Package org.springframework.data.mongodb.core.aggregation

Class MergeOperation

java.lang.Object

org.springframework.data.mongodb.core.aggregation.MergeOperation

All Implemented Interfaces:

AggregationOperation, FieldsExposingAggregationOperation, FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

public class MergeOperation
extends Object
implements FieldsExposingAggregationOperation, FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

Encapsulates the $merge-operation.

We recommend to use the builder via builder() instead of creating instances of this class directly.

Since:

3.0

Author:

Christoph Strobl

See Also:

• MongoDB Documentation

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MergeOperation.MergeOperationBuilder	Builder API to construct a MergeOperation.
static class	MergeOperation.MergeOperationTarget	Value Object representing the into field of a $merge aggregation stage.
static class	MergeOperation.UniqueMergeId	Value object representing the unique id used during the merge operation to identify duplicates in the target collection.
static class	MergeOperation.WhenDocumentsDontMatch	Value Object specifying how to deal with a result document that do not match an existing document in the collection based on the fields of the on property describing the unique identifier.
static class	MergeOperation.WhenDocumentsMatch	Value Object specifying how to deal with a result document that matches an existing document in the collection based on the fields of the on property describing the unique identifier.

Nested classes/interfaces inherited from interface org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation

FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

Constructor Summary

Constructors

Constructor	Description
MergeOperation(MergeOperation.MergeOperationTarget into, MergeOperation.UniqueMergeId on, VariableOperators.Let let, MergeOperation.WhenDocumentsMatch whenMatched, MergeOperation.WhenDocumentsDontMatch whenNotMatched)	Create new instance of MergeOperation.

Method Summary

Modifier and Type	Method	Description
static MergeOperation.MergeOperationBuilder	builder()	Access the builder API to create a new instance of MergeOperation.
ExposedFields	getFields()	Returns the fields exposed by the AggregationOperation.
String	getOperator()	Return the MongoDB operator that is used for this AggregationOperation.
boolean	inheritsFields()
static MergeOperation	mergeInto(String collection)	Simplified form to apply all default options for $merge (including writing to a collection in the same database).
org.bson.Document	toDocument(AggregationOperationContext context)	Turns the AggregationOperation into a Document by using the given AggregationOperationContext.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.data.mongodb.core.aggregation.AggregationOperation

toPipelineStages

Constructor Details

MergeOperation

public MergeOperation(MergeOperation.MergeOperationTarget into,
 MergeOperation.UniqueMergeId on,
 @Nullable
 VariableOperators.Let let,
 @Nullable
 MergeOperation.WhenDocumentsMatch whenMatched,
 @Nullable
 MergeOperation.WhenDocumentsDontMatch whenNotMatched)

Create new instance of MergeOperation.

Parameters:

into - the target (collection and database)

on - the unique identifier. Can be null.

let - exposed variables for MergeOperation.WhenDocumentsMatch.updateWith(Aggregation). Can be null.

whenMatched - behavior if a result document matches an existing one in the target collection. Can be null.

whenNotMatched - behavior if a result document does not match an existing one in the target collection. Can be null.

Method Details

mergeInto

public static MergeOperation mergeInto(String collection)

Simplified form to apply all default options for $merge (including writing to a collection in the same database).

Parameters:

collection - the output collection within the same database.

Returns:

new instance of MergeOperation.

builder

public static MergeOperation.MergeOperationBuilder builder()

Access the builder API to create a new instance of MergeOperation.

Returns:

new instance of MergeOperation.MergeOperationBuilder.

toDocument

public org.bson.Document toDocument(AggregationOperationContext context)

Description copied from interface: AggregationOperation

Turns the AggregationOperation into a Document by using the given AggregationOperationContext.

Specified by:

toDocument in interface AggregationOperation

Parameters:

context - the AggregationOperationContext to operate within. Must not be null.

Returns:

the Document

getOperator

public String getOperator()

Description copied from interface: AggregationOperation

Return the MongoDB operator that is used for this AggregationOperation. Aggregation operations should implement this method to avoid document rendering.

Specified by:

getOperator in interface AggregationOperation

Returns:

the operator used for this AggregationOperation.

getFields

public ExposedFields getFields()

Description copied from interface: FieldsExposingAggregationOperation

Returns the fields exposed by the AggregationOperation.

Specified by:

getFields in interface FieldsExposingAggregationOperation

Returns:

will never be null.

inheritsFields

public boolean inheritsFields()

Specified by:

inheritsFields in interface FieldsExposingAggregationOperation

Specified by:

inheritsFields in interface FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation

Returns:

true to conditionally inherit fields from previous operations.