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IAggregateFluentExtensionsLookupTResult Method (IAggregateFluentTResult, String, FieldDefinitionTResult, FieldDefinitionBsonDocument, FieldDefinitionBsonDocument)

Appends a lookup stage to the pipeline.

Namespace:  MongoDB.Driver
Assembly:  MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.21.0+5a9c3311e158910b88195f290e6d4b1b2715d2b2
Syntax
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public static IAggregateFluent<BsonDocument> Lookup<TResult>(
	this IAggregateFluent<TResult> aggregate,
	string foreignCollectionName,
	FieldDefinition<TResult> localField,
	FieldDefinition<BsonDocument> foreignField,
	FieldDefinition<BsonDocument> as
)

Parameters

aggregate
Type: MongoDB.DriverIAggregateFluentTResult
The aggregate.
foreignCollectionName
Type: SystemString
Name of the foreign collection.
localField
Type: MongoDB.DriverFieldDefinitionTResult
The local field.
foreignField
Type: MongoDB.DriverFieldDefinitionBsonDocument
The foreign field.
as
Type: MongoDB.DriverFieldDefinitionBsonDocument
The field in the result to place the foreign matches.

Type Parameters

TResult
The type of the result.

Return Value

Type: IAggregateFluentBsonDocument
The fluent aggregate interface.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IAggregateFluentTResult. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).
See Also