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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: 2.20.0+ee01960089f28ea1b501690df5fc9f6318a70242
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