What is CLR:
 
 
The common language runtime (CLR) provides the execution environment for all .NET Framework code. The CLR provides various functions and services required for program execution, including just-in-time (JIT) compilation, allocating and managing memory, enforcing type safety, exception handling, thread management, and security.
 
 
When to use CLR integration in SQL Server
- If your procedure or function feature in complex logic.
 - If you want to access class library which you develop using .Net programming language.
 
 
Steps to use CLR Integration in SQL Server
 
 
Step 1 Enable CLR in Sql Server
 
- EXEC sp_configure 'clr enabled', '1'  
 
 
Step 2 CLR re cofigure
Step 3 Enable trustworthy for unsafe permission on database
 - ALTER DATABASE <Database_Name> SET TRUSTWORTHY ON;  
 
Step 4 Create Managed code (class library) in C# to show output with example.
- using System;  
 - using System.Data.SqlTypes;  
 - using Microsoft.SqlServer.Server;  
 - namespace CLRLibraryFunction  
 - {  
 - public class UserDefinedFunctions  
 - {  
 - [SqlFunction(Name = "GetLongDate",  
 - DataAccess = DataAccessKind.None)]  
 - public static SqlString GetLongDate(SqlDateTime DateVal)  
 - {  
 - return DateVal.Value.ToLongDateString();  
 - }  
 - }  
 - }  
 
Step 5 Create CLR assembly in SQL Server
- CREATE ASSEMBLY GetLongDateAssembly  
 - FROM 'F:\CLRLibraryFunction.dll'WITH PERMISSION_SET = UNSAFE  
 
Step 6 Create CLR function in SQL Server
- CREATE FUNCTION GetLongDate(@d as DateTime)  
 - RETURNS nVarchar(50)  
 - AS EXTERNAL NAME GetLongDateAssembly.[CLRLibraryFunction.UserDefinedFunctions].GetLongDate  
 
Step 7 Execute Function with employee table
- SELECT dbo.GetLongDate(<date>)  
 
That's all. If you have any query or suggestion, kindly revert back with comments.
 
Thanking you.