How do you calculate between records

[Mark Lyon]

I like this program. Seems like a good Bento replacement. So, How can I achieve the following:

I’ve got a gasoline database with fields for: date, gallons, odometer, mileage

Then individual records for:
Monday’s date, gallons, odometer, mileage
Tuesday’s date, gallons, odometer, mileage
Wednesday’s date, gallons, odometer, mileage

To enter Tuesday’s mileage, I must subtract Monday’s odometer from Tuesday’s odometer. How can I do this? Formulas work only for individual records. I had the same problem with Bento. Never found an answer. Maybe I don’t have the right concept.

TIA

[Brendan]

Hi Mark,

Tap Forms doesn’t have access to other records from within a Calculation field. So this sort of calculation won’t work unfortunately. But I have been asked about it a few times before, so it may come in a future update. No timeline on that though.

You can do calculations across records, but those are aggregate calculations such as Total, Average, Minimum, or Maximum. You set that up using the Calculation Type property of your numeric fields.

Thanks,

Brendan

[Mark Lyon]

Thanks, Brendan.

I thought I read somewhere Tap Forms could do this. One of the reasons I was excited to get the app. But, okay. No way to access unique record id in a formula. I used Filemaker for a long while but it’s more than I need–expect for this single function.

ciao,
Mark

[Author]

Posts