SQL Server CLR Integration - A Beginner's Guide

SQL Server Common Language Runtime (CLR) Integration allows you to write and execute .NET code within the database engine. In this beginner's guide, we'll explore the basics of SQL Server CLR Integration, its use cases, and provide sample code snippets to help you get started with creating and deploying CLR objects in SQL Server.

Why Use SQL Server CLR Integration?

SQL Server CLR Integration provides several advantages:

• Extended Functionality: You can implement custom functions, procedures, and data types in .NET, extending SQL Server's capabilities.
• Performance: Some operations can be performed more efficiently in .NET than in T-SQL.
• Reusability: You can reuse existing .NET libraries and code in your SQL Server database.

Enabling CLR Integration

Before using CLR objects, you must enable CLR Integration at the database level:

-- Enable CLR Integration at the database level
ALTER DATABASE YourDatabase
SET TRUSTWORTHY ON;
    

Creating a Simple CLR Stored Procedure

Let's create a simple CLR stored procedure that returns the sum of two numbers:

using System;
using System.Data;
using System.Data.SqlClient;
using Microsoft.SqlServer.Server;
public partial class StoredProcedures
{
    [SqlProcedure]
    public static void SumNumbers(SqlInt32 a, SqlInt32 b, out SqlInt32 result)
    {
        result = a + b;
    }
}
    

Deploying CLR Assemblies

After writing your CLR code, you need to deploy the assembly to SQL Server:

-- Deploy the CLR assembly
CREATE ASSEMBLY MyClrAssembly
FROM 'C:\Path\To\MyClrAssembly.dll'
WITH PERMISSION_SET = SAFE;
    

Creating and Using CLR Objects

Once the assembly is deployed, you can create and use CLR objects in SQL Server:

-- Create a CLR stored procedure
CREATE PROCEDURE dbo.SumNumbersCLR
    @a INT, @b INT, @result INT OUTPUT
AS EXTERNAL NAME MyClrAssembly.StoredProcedures.SumNumbers;
    

What's Next?

As you become more proficient with SQL Server CLR Integration, explore advanced topics such as debugging CLR code, security considerations, and real-world use cases for CLR objects in SQL Server.