---
title: "CLR User-Defined Functions | Microsoft Docs"
description: SQL Server CLR integration allows you to create user-defined scalar-valued, table-valued, and aggregate functions in any .NET Framework programming language.
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ms.date: "03/14/2017"
ms.prod: sql
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ms.technology: clr
ms.topic: "reference"
helpviewer_keywords: 
  - "building database objects [CLR integration], user-defined functions"
  - "functions [CLR integration]"
  - "common language runtime [SQL Server], user-defined functions"
  - "database objects [CLR integration], user-defined functions"
  - "user-defined functions [CLR integration]"
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author: "rothja"
ms.author: "jroth"
---
# CLR User-Defined Functions
 [!INCLUDE [SQL Server](../../includes/applies-to-version/sqlserver.md)]
  User-defined functions are routines that can take parameters, perform calculations or other actions, and return a result. Beginning with [!INCLUDE[ssVersion2005](../../includes/ssversion2005-md.md)], you can write user-defined functions in any [!INCLUDE[msCoName](../../includes/msconame-md.md)] .NET Framework programming language, such as [!INCLUDE[msCoName](../../includes/msconame-md.md)] Visual Basic .NET or [!INCLUDE[msCoName](../../includes/msconame-md.md)] Visual C#.  
  
 There are two types of functions: scalar, which returns a single value, and table-valued, which returns a set of rows.  
  
 The following table lists the topics in this section.  
  
 [CLR Scalar-Valued Functions](../../relational-databases/clr-integration-database-objects-user-defined-functions/clr-scalar-valued-functions.md)  
 Covers implementation requirements and examples of scalar-valued functions.  
  
 [CLR Table-Valued Functions](../../relational-databases/clr-integration-database-objects-user-defined-functions/clr-table-valued-functions.md)  
 Discusses how to implement and use table-valued functions (TVFs), as well as differences between [!INCLUDE[tsql](../../includes/tsql-md.md)] and common language runtime (CLR) TVFs.  
  
 [CLR User-Defined Aggregates](../../relational-databases/clr-integration-database-objects-user-defined-functions/clr-user-defined-aggregates.md)  
 Describes how to implement and use user-defined aggregates.  
  
## See Also  
 [User-Defined Functions](../../relational-databases/user-defined-functions/user-defined-functions.md)