Performing a Calculation on two fields

[Troogroove]

This is going to be a simple one for someone, but it is proving to be a pain for me. I have two collums in a table, one that is a value another is a quantity, i have another field that totals the two fields. This works fine and shows the total but it does not store the total into the database, how can i get it to do this.

In the Total field the control source is "=[Cost]*[Quantity]" i have tried to set it too TotalCost=[Cost]*[Quantity] but this gives me errors

Thanks for looking

 

[neileg]

The simple answer is that you don't store it. Just calculate the value in a form or query any time you need it.

 

[The_Doc_Man]

neileg's answer is correct but so brief you might be confused. The rest of the story is that anytime you need the computation, use the query as your recordsource rather than the table. Because whatever takes a recordsource usually doesn't know or care that you were using a query or a table. BOTH are perfectly valid recordsources. And with exceedingly rare exceptions, you never EVER store a computed value in a table.

 

[boblarson]

And, just as a technical side note -

When setting a controlsource normally there is NOTHING placed on the left side of the equals (=) sign and the equals sign is not used when binding to a field in the form's recordsource.

check out this post for more complete info (and the help file too)
http://www.access-programmers.co.uk/forums/showthread.php?t=119465&highlight=controlsource