IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
               WHERE SYSCOLUMNS.NAME = 'PASIF' AND SYSOBJECTS.name = 'TBANKAHESAP')
ALTER TABLE dbo.TBANKAHESAP ADD PASIF bit  NOT NULL CONSTRAINT [DF_TBANKAHESAP_PASIF]  DEFAULT ((0))
go