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Create CLR Triggers

You can create a database object inside SQL Server that is programmed in an assembly created in the Microsoft .NET Framework common language runtime (CLR). Database objects that can leverage the rich programming model provided by the CLR include DML triggers, DDL triggers, stored procedures, functions, aggregate functions, and types.

Creating a CLR trigger (DML or DDL) in SQL Server involves the following steps:

  • Define the trigger as a class in a .NET Framework-supported language. For more information about how to program triggers in the CLR, see CLR Triggers. Then, compile the class to build an assembly in the .NET Framework using the appropriate language compiler.

  • Register the assembly in SQL Server using the CREATE ASSEMBLY statement. For more information about assemblies in SQL Server, see Assemblies (Database Engine).

  • Create the trigger that references the registered assembly.


Deploying a SQL Server Project in Microsoft Visual Studio registers an assembly in the database that was specified for the project. Deploying the project also creates CLR triggers in the database for all methods annotated with the SqlTrigger attribute. For more information, see Deploying CLR Database Objects.


The ability of SQL Server to execute CLR code is off by default. You can create, alter, and drop database objects that reference managed code modules, but these references will not execute in SQL Server unless the clr enabled Option is enabled using sp_configure (Transact-SQL).

To create, modify, or drop an assembly

To create a CLR trigger

See Also


DML Triggers

Data Access from CLR Database Objects

Other Resources

Common Language Runtime (CLR) Integration Programming Concepts