In SQL Server, you can use the CREATE ASSEMBLY statement to load a .NET assembly (DLL) into the SQL Server database, which allows you to define and execute .NET functions and stored procedures within SQL Server.
Here are the steps to create an assembly from a .NET DLL using the CREATE ASSEMBLY statement:
Step 1: Prepare the .NET Assembly
Ensure that you have the .NET assembly (DLL) that you want to load into SQL Server. The assembly must be built in a compatible version of .NET and be accessible from the SQL Server instance.
Step 2: Grant Permissions
Make sure you have the necessary permissions to execute the CREATE ASSEMBLY statement. You need to have the appropriate rights, typically impersonating or being a member of the db_owner role or sysadmin role.
Step 3: Use CREATE ASSEMBLY Statement
The basic syntax for the CREATE ASSEMBLY statement is as follows:
CREATE ASSEMBLY [schema_name].[assembly_name]
FROM 'disk_path_to_your_dll'
WITH PERMISSION_SET = [permission_set]
- schema_name: The schema where you want to create the assembly. Generally, you can use dbo.
- assembly_name: A name for the assembly.
- disk_path_to_your_dll: The full path to the .NET DLL file on the disk.
- permission_set: The level of permission for the assembly, which can be SAFE, EXTERNAL_ACCESS, or UNSAFE.
Example
Here is an example of how to create an assembly in SQL Server:
CREATE ASSEMBLY dbo.MyAssembly
FROM 'C:\Path\To\Your\Assembly.dll'
WITH PERMISSION_SET = SAFE;
Notes
- Path: The path to the DLL should be accessible to SQL Server. The SQL Server service account must have permission to read the specified file.
- Permission Set: Use SAFE for assemblies that do not access external resources or perform unsafe operations. Use EXTERNAL_ACCESS if the assembly requires access to external resources, and UNSAFE if your assembly performs operations that can expose data or system resources.
Step 4: Verify Assembly Creation
You can verify that the assembly has been created and is registered with SQL Server using the following query:
SELECT *
FROM sys.assemblies
WHERE name = 'MyAssembly';
Step 5: Create Functions / Stored Procedures
Once the assembly is created, you can create SQL Server functions, stored procedures, or triggers based on the methods defined in your assembly.
Example of Creating a Function
Assuming you have a method named AddNumbers in your assembly:
CREATE FUNCTION dbo.AddNumbers(@a INT, @b INT)
RETURNS INT
AS EXTERNAL NAME dbo.MyAssembly.[Namespace.ClassName].AddNumbers;
Conclusion
By following these steps, you should be able to successfully create an assembly from a .NET DLL in SQL Server using the CREATE ASSEMBLY statement. Be sure to consider security implications when loading and executing .NET code in your SQL Server instance.