IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
              WHERE SYSCOLUMNS.NAME = 'ONCELIKLI' AND SYSOBJECTS.name = 'HTEDAVITABELA')
ALTER TABLE dbo.[HTEDAVITABELA] ADD ONCELIKLI BIT NULL

GO

IF NOT EXISTS (SELECT * FROM SYSCOLUMNS INNER JOIN SYSOBJECTS ON SYSOBJECTS.id = SYSCOLUMNS.id 
              WHERE SYSCOLUMNS.NAME = 'ONCELIKLI' AND SYSOBJECTS.name = 'TALEPFIS')
ALTER TABLE dbo.[TALEPFIS] ADD ONCELIKLI BIT NULL

GO