IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
              WHERE SYSCOLUMNS.NAME = 'ENTEGRASYONSORGUTARIH' AND SYSOBJECTS.name = 'HKIMLIKGIZLILIK')
ALTER TABLE HKIMLIKGIZLILIK ADD ENTEGRASYONSORGUTARIH DATETIME NULL
GO