SQL-Query: left join?

[key]

Hi Access-Friends,

I'm stuck with the following problem: in Tab1 are Account No. and Amounts and it is possible to change the amounts. The changed Number is stored in Tab2.
Now, I want to show the actual amounts, it means: if there is a changedAmount in Tab2 show the calculated amount. Example:
Tab1: Amount: 5000, Month: January, Year: 2002
Tab2: ChangedNumber: 2000 , Month: January, Year: 2002

result should be: 3000

if there is no ChangedNumber in Tab2 show 5000.

I've tried to use isNull, iif functions as well es left join - nothing works!

Could someone help me?

Many thanx,

Key


P. S. Here are the tables:

Tab1(AccNo, Amount, Month, Year) and
Tab2 (AccNo, ChangedAmount, Month, Year)

 

[key]

quick question..

First of all: thanx a lot, it works!!
To make myself happy: how do I implement a Sum function - because, an amount can be changed 0, one or more times, so what I need to do is something like:

(Amount)- Sum(Nz(ChangedAmount,0)...

But this doesn't work.

Many, many thanx,

Key