مرحله اول
SELECT dbo.TbFactor.nFactor, SUM(dbo.TbKala.nMablagh) - dbo.TbFactor.nTakhfif AS Tafazol
FROM dbo.TbFactor LEFT OUTER JOIN
dbo.TbKala ON dbo.TbFactor.nFactor = dbo.TbKala.nFactor
GROUP BY dbo.TbFactor.nFactor, dbo.TbFactor.nTakhfif
مرحله دوم
SELECT TbFactor.nFactor, TbKala.nKala, TbKala.nMablagh, VIEW_Tafazol.Tafazol
FROM TbFactor LEFT OUTER JOIN
VIEW_Tafazol ON TbFactor.nFactor = VIEW_Tafazol.nFactor LEFT OUTER JOIN
TbKala ON TbFactor.nFactor = TbKala.nFactor
البته با استفاده از ايجاد يك تابع هم ميشه بجاي query اول استفاده كرد.