IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
               WHERE SYSCOLUMNS.NAME = 'MDLISLEMSIRANO' AND SYSOBJECTS.name = 'MDLKESINTIYAPILMISISLEMLER')
ALTER TABLE dbo.MDLKESINTIYAPILMISISLEMLER ADD
	MDLISLEMSIRANO nvarchar(20) NULL
GO