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MSDN Library

Queryable.Concat(TSource) Method

Concatenates two sequences.

Namespace:  System.Linq
Assemblies:   System.Linq.Queryable (in System.Linq.Queryable.dll)
  System.Core (in System.Core.dll)

static member Concat : 
        source1:IQueryable<'TSource> * 
        source2:IEnumerable<'TSource> -> IQueryable<'TSource> 

Type Parameters


The type of the elements of the input sequences.


Type: System.Linq.IQueryable(TSource)

The first sequence to concatenate.

Type: System.Collections.Generic.IEnumerable(TSource)

The sequence to concatenate to the first sequence.

Return Value

Type: System.Linq.IQueryable(TSource)
An IQueryable(T) that contains the concatenated elements of the two input sequences.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IQueryable(TSource). 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).


source1 or source2 is a null reference (Nothing in Visual Basic).

The Concat(TSource)(IQueryable(TSource), IEnumerable(TSource)) method generates a MethodCallExpression that represents calling Concat(TSource)(IQueryable(TSource), IEnumerable(TSource)) itself as a constructed generic method. It then passes the MethodCallExpression to the CreateQuery(TElement)(Expression) method of the IQueryProvider represented by the Provider property of the source1 parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling Concat(TSource)(IQueryable(TSource), IEnumerable(TSource)) depends on the implementation of the type of the source1 parameter. The expected behavior is that the elements in source2 are concatenated to those of source1 to create a new sequence.

The following code example demonstrates how to use Concat(TSource)(IQueryable(TSource), IEnumerable(TSource)) to concatenate two sequences.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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