Using MERGE Command in Stored Procedure

MERGE command is a very useful sql command when we need to perform INSERT/UPDATE/DELETE on a database object based on condition. Instead of writing different code blocks for INSERT/UPDATE/DELETE, we can merge the commands. DotNetSpider has an article regarding MERGE command. Please reffer:
http://www.dotnetspider.com/resources/44872-SQL-SERVER-MERGE-STATEMENT.aspx

But in this code snippet I will show how to use this MERGE command in Stored Procedure. Here it goes:

SET QUOTED_IDENTIFIER ON;
SET ANSI_NULLS ON;
SET NOCOUNT ON;
GO

IF EXISTS (SELECT *
		FROM INFORMATION_SCHEMA.ROUTINES
		WHERE ROUTINE_NAME = 'SET_REVERT_FLAG'
		AND ROUTINE_TYPE = 'PROCEDURE')
BEGIN
	PRINT 'Dropping stored procedure SET_REVERT_FLAG.';
	DROP PROCEDURE SET_REVERT_FLAG;
END

GO

CREATE PROCEDURE [dbo].[SET_REVERT_FLAG](
@ID bigint,
@IsFlag bit
)
AS
BEGIN

	DECLARE @Submit_Flag table (ID bigint, IsFlag bit);

	INSERT INTO @Submit_Flag VALUES(@ID,@IsFlag);

	MERGE [Submissions_Flag] AS flagTable
	USING @Submit_Flag AS sourceTable
	ON flagTable.ID = sourceTable.ID 

	WHEN MATCHED THEN
	  UPDATE
	     SET flagTable.IsFlag = @IsFlag,
	     flagTable.DTS = getdate()
		  
	WHEN NOT MATCHED BY TARGET THEN
	  INSERT (ID, IsFlag, DTS)
	  VALUES (sourceTable.ID , sourceTable.IsFlag, getdate());
 
  END
  GO
  ---------------------------------------------------------------------------
--	END OF CREATE STATEMENTS.
--	METADATA AND SUCCESS/ERROR MESSAGES BELOW.
---------------------------------------------------------------------------
IF EXISTS (SELECT *
		FROM INFORMATION_SCHEMA.ROUTINES
		WHERE ROUTINE_NAME = 'SET_REVERT_FLAG'
		AND ROUTINE_TYPE = 'PROCEDURE' )
BEGIN
	PRINT 'Stored procedure SET_REVERT_FLAG created successfully.';	
END
ELSE
BEGIN
	PRINT 'ERROR: Failed to create stored procedure SET_REVERT_FLAG.';
END
GO