Summing a Sum field

Hi,
I'm trying to Sum a field which is a Sum itself.
MySQL doesn't seems to like it.

Any ideas?

The SQL is (a bit complex):
SELECT Sum(ti.triQuantity) * i.ingQuantity, d.drnId, d.drnName
FROM tblIngredients as i
INNER JOIN tbldrinks AS d ON i.ingIngredientNum = d.drnId
INNER JOIN tblTransactionItems as ti ON d.drnId = ti.triDrinkId
INNER JOIN tblTransaction AS t ON ti.triTAId = t.trcId
WHERE i.ingDrinkNum IN (SELECT ingDrinkNum FROM tblIngredients WHERE
ingIngredientNum = 45)

Help would be appreciated.
Thanx

add

GROUP BY i.ingQuantity, d.drnId, d.drnName

I'm afraid I've posted the wrong SQL. Sorry.
Here is the correct one:
SELECT Sum(ti.triQuantity) * i.ingQuantity as TotalQTY, d1.drnId, d1.drnName
FROM tblDrinks as d1
INNER JOIN tblIngredients as i ON d1.drnId = i.ingIngredientNum
INNER JOIN tbldrinks AS d ON i.ingDrinkNum = d.drnId
INNER JOIN tblTransactionItems as ti ON d.drnId = ti.triDrinkId
WHERE i.ingDrinkNum IN (48, 47)
GROUP BY d1.drnId, d.drnId

The problem is that the query returns sums of the same item, where as I want to get the total sum of that item (of all the occurrences)

Thanx

keep looking at your groups

your GROUP BY list of columns must be all the non-aggregate columns in the SELECT list

thus, it must be --

GROUP BY i.ingQuantity, d1.drnId, d1.drnName

now, if that's the wrong grouping, then you have to address that