Subtract from Previous Row

[lambo102]

Hopefully this isn't a big deal but I have a query that shows various data as you may expect.



Date Number1
1/01/11 12345
1/15/11 19182

I'm looking for a way to show the difference from row to row. For example, I want to add a column after Number 1 that shows me how much Number 1 increased (or decreased) from the previous row.

This is one of those painfully easy things in Excel, but I'm not sure how to tell Access to do it.

Please help?

[NTC]

databases are different then excel sheets - that's for sure. really isn't an Access issue per se - any database has the same issues.

a query presents data. it isn't the ideal vehicle for multi line actions - until you get into high end self joins - but lets not go there for the moment.

in a form or report - it is very simple to do math in the footer or group footer. If you have an Access textbook easily found at Amazon or any large book store - - they all go thru this.

back to a query; in a query one can easily do math within a single row using a calculated field (also in your text book). the key then is how you get the needed data all in the same row. And for that it would require a single unique value in both records (and no other records) that you can join on. you can put the same table up twice in query design view and then join.

Hope it helps.