How to: Create and Run a SQL Server User-Defined Function by using Common Language Run-time Integration
Create a SQL user-defined function by adding a User-Defined Function to a SQL Server Common Language Run-time (SQL CLR) database project. After successful deployment, the user-defined function can be called and executed.
Note
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Creating SQL Server User-Defined Functions
To build and deploy this function using Visual Studio
Open an existing SQL CLR Database Project, or create a new one. For more information, see How to: Create a Project for Database Objects that Use SQL Server Common Language Run-time Integration.
On the Project menu, select Add New Item.
In the Add New Item dialog box, select User-Defined Function.
Type a Name for the new user-defined function.
Add code to run when the user-defined function is executed. See the first example that follows this procedure.
In Solution Explorer, open the TestScripts folder and double-click the Test.sql file to open it for editing. Add code to execute your user-defined function. See the second example that follows this procedure.
Note
You can specify other scripts as your default debug script. For more information, see How to: Edit the Test.sql Script to Run Objects that use SQL Server Common Language Run-time Integration.
Deploy the user-defined function to the SQL Server. For more information, see How to: Deploy SQL Server CLR Integration Database Project Items to a SQL Server.
Important
SQL Server 2005 and SQL Server 2008 only support SQL Server projects that were built with the 2.0, 3.0, or 3.5 version of the .NET Framework. If you try to deploy a SQL Server project to SQL Server 2005 or SQL Server 2008, an error appears: Deploy error (SQL01268): .NET SqlClient Data Provider: Msg 6218, Level 16, State 3, Line 1 CREATE ASSEMBLY for assembly 'AssemblyName' failed because assembly 'AssemblyName' failed verification. Check if the referenced assemblies are up-to-date and trusted (for external_access or unsafe) to execute in the database (where AssemblyName is the name of the assembly that you are deploying). For more information, see How to: Create a Project for Database Objects that Use SQL Server Common Language Run-time Integration.
Press F5 to debug the user-defined function by executing it on the SQL Server.
Description
The following code example creates a user-defined scalar function called addTax that takes a price as a parameter, adds sales tax to it, and returns the price plus the tax.
After you create the function, deploy it to the SQL Server. For more information, see How to: Deploy SQL Server CLR Integration Database Project Items to a SQL Server
Code
Imports System.Data.SqlTypes
Imports Microsoft.SqlServer.Server
Partial Public Class UserDefinedFunctions
Public Const SALES_TAX As Double = 0.086
<SqlFunction()>
Public Shared Function addTax(ByVal originalAmount As SqlDouble) As SqlDouble
Dim taxAmount As SqlDouble = originalAmount * SALES_TAX
Return originalAmount + taxAmount
End Function
End Class
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
public partial class UserDefinedFunctions
{
public const double SALES_TAX = .086;
[SqlFunction()]
public static SqlDouble addTax(SqlDouble originalAmount)
{
SqlDouble taxAmount = originalAmount * SALES_TAX;
return originalAmount + taxAmount;
}
}
Description
Add code to test the user-defined function to the Test.sql file in the TestScripts folder in your project. For example, to test this function, use a query, such as "SELECT dbo.addTax(10)." You should see the returned value "10.86."
Code
SELECT dbo.addTax(10)
See Also
Tasks
How to: Create and Run a SQL Server Stored Procedure by using Common Language Run-time Integration
How to: Create and Run a SQL Server Trigger by using Common Language Run-time Integration
How to: Create and Run a SQL Server Aggregate by using Common Language Run-time Integration
How to: Create and Run a SQL Server User-Defined Type by using Common Language Run-time Integration
Walkthrough: Creating a Stored Procedure in Managed Code
How to: Debug a SQL Server CLR Integration Stored Procedure
Reference
Attributes for SQL Server CLR Integration Database Projects and Database Objects
Concepts
Introduction to SQL Server CLR Integration (ADO.NET)
Advantages of Using Managed Code to Create Database Objects
Creating SQL Server Objects in Managed Code