IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
              WHERE SYSCOLUMNS.NAME = 'FOYGONDERILDI' AND SYSOBJECTS.name = 'HSENCARDDOKUMAN')
ALTER TABLE HSENCARDDOKUMAN ADD FOYGONDERILDI bit NOT NULL CONSTRAINT DF_HSENCARDDOKUMAN_FOYGONDERILDI DEFAULT 0
go