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