The formula that I used is:
And is the portal's table COSTTABLE?
Did you define this calculation field in CostTable or in the parent record? Sum ( RelatedTableOccurrence::FieldName ), when defined in the parent table, will compute the total of the specified field for all related tables. When you define it in the related table, all you get is the same result as just using: FieldName as your reference. (It's functionally the same as specifying Sum ( 4 ). which is the same as just using 4. )
Yes, it is the portal table. I did defined the calculation for the Amount in the parent record.
Then it should compute the total for all the related records--which will be all the items in your portal unless you filter the portal.
Did you use a field of type calculation or is this a number field with an auto-entered calculation?
It must be a field of type calculation, not auto-entered into a number field or it won't update when values in the related table are added/removed/changed.
Thanks Phil, I got the addition of the fields in the portal working but when I do the next day where the TotalCost from the previous day will be the value of the Previous doesn't work.
I got it now working Phil, thank you again. I didn't define my Previous correctly, but now it's working.