Creating an Assembly

Creating an assembly involves several steps, including setting up the necessary permissions, writing the .NET code, and then loading the assembly into SQL Server. Here’s a step-by-step guide to help you create an assembly in SQL Server:

1. Prepare the .NET Assembly

First, you need to create a .NET assembly (DLL) using a .NET language like C#. Here’s a simple example:

Create a C# Class Library

1. Open Visual Studio and create a new Class Library project.
2. Write your code. For example, you can create a simple method that adds two numbers:

using System;

namespace SqlServerAssembly
{
    public class MathFunctions
    {
        public static int Add(int a, int b)
        {
            return a + b;
        }
    }
}

3. Build the project to generate the DLL file. Note the path where the DLL is saved.

2. Enable CLR Integration

By default, CLR integration is disabled in SQL Server. You need to enable it using the following SQL commands:

sp_configure 'clr enabled', 1;
RECONFIGURE;

3. Load the Assembly

Next, you need to load the assembly into SQL Server.

1. Open SQL Server Management Studio (SSMS).
2. Connect to your database.
3. Use the following T-SQL commands to create an assembly and reference the DLL you created:

CREATE ASSEMBLY [SqlServerAssembly]
FROM 'C:\path\to\your\assembly\SqlServerAssembly.dll'
WITH PERMISSION_SET = SAFE;

4. Create Functions or Procedures to Use the Assembly

After loading the assembly, you need to create functions or stored procedures to call the methods from the assembly.

Create a SQL function that uses the Add method from your assembly:

CREATE FUNCTION dbo.AddNumbers (@a INT, @b INT)
RETURNS INT
AS EXTERNAL NAME [SqlServerAssembly].[SqlServerAssembly.MathFunctions].[Add];

5. Test the Assembly

Finally, you can test the function to ensure it works correctly.

SELECT dbo.AddNumbers(5, 10);

Summary

• Create a .NET assembly: Write and compile a class library in a .NET language like C#.
• Enable CLR: Use sp_configure to enable CLR integration.
• Load the assembly: Use the CREATE ASSEMBLY command to load your DLL into SQL Server.
• Create SQL functions or procedures: Use CREATE FUNCTION or CREATE PROCEDURE to expose the methods from your assembly.
• Test the function: Call your function to verify that it works as expected.

This guide covers the basic steps required to create and use an assembly. Depending on your specific needs, you may need to adjust permissions, handle complex types, or manage different versions of assemblies.