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IAggregateFluentExtensions.Lookup<TResult> Method (IAggregateFluent<TResult>, String, FieldDefinition<TResult>, FieldDefinition<BsonDocument>, FieldDefinition<BsonDocument>)

Appends a lookup stage to the pipeline.

Namespace:  MongoDB.Driver
Assembly:  MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.22.0+75246110ed1247226fcc7f8eb2c54ffab745693e
Syntax
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.Driver.IAggregateFluent<TResult>
The aggregate.
foreignCollectionName
Type: System.String
Name of the foreign collection.
localField
Type: MongoDB.Driver.FieldDefinition<TResult>
The local field.
foreignField
Type: MongoDB.Driver.FieldDefinition<BsonDocument>
The foreign field.
as
Type: MongoDB.Driver.FieldDefinition<BsonDocument>
The field in the result to place the foreign matches.

Type Parameters

TResult
The type of the result.

Return Value

Type: IAggregateFluent<BsonDocument>
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 IAggregateFluent<TResult>. 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