When I do this SELECT:

SELECT sum( a.discount * b.price * b.quantity * ( 1 - b.discount2 ) * ( 1 -
b.discount3 )) FROM a, b ......

Discount, discount2, and discount3 - decimal(8,4)
Price and Quantity - decimal(15,2)

I found this error: "Integer overflow. The result of an integer operation
caused the most significant bit of the result to carry."

How to solve it?

TIA.

Regards,

--chris