Re: Calculation from time stamps through to amount due

[Peter Brawley]

> set new amount_due = (elapsed * rate)'
> throws an error.

And we mayn't know what that error message says!?

> how to "check for elapsed" before doing the next calculation

A Trigger can't do a raw Select, so set user variables to the values you are tracking, and after the Trigger has run, select the user vars to see what they contain.

The Trigger has no control over column values delivered to it, so your code has to handle the possibility of Nulls and outlandish values.