Query: Subtract totals from different tables

[joannakf]

I am writing a total query and I keep getting the error message that I am trying to execute a function without a specified expression.



I have a table that says:
BLDG Count of A
1 1
2 3
3 1

And a Query That says:
BLDG Count of B
1 1
2 2

How do I write an expression that subtracts Count of B from Count of A only when the BLDG matches but displayes all of the totals for the first table.

Thanks in advance!!

[aytee111]

Show us the query

[joannakf]

I attached a screen shot of the query...thanks!

[aytee111]

You are trying to do too much at one time. Get each individual piece working one at a time.

First, create a query showing all the buildings you want to see from the correct place (I think your join is the wrong way around). Don't move on until you have got that working.

Then, your expression would be something like this:
IIf(Not IsNull(Qry.Building),Sum(whatever))
which means that if there is a valid record in the qry then it will sum it)