I have the following in a column:
SUM(
SELECT(
Payments[Agent commission],
And(
([Agent] = [_THISROW].[ID]),
([Closing Date] < [_THISROW].[Anniversary Date]),
([Closing Date] >= [_THISROW].[Previous Anniversary])
)
)
)
This same expression works in a virtual column, but not in an actual column. The actual column is just blank. Can anyone educate me?
If you have entered the expression in the real column after all the table rows are existing , then each row will need to be edited to update the value in that row.
If you want the values from the expression to reflect in all rows of a table, you could also use reference actions / bulk actions or use an API to update the value in the said column in multiple records at a time without needing to open and save each record.
App Formulas in real columns only evaluate when that record is edited. Virtual Columns re-evaluate upon every sync.
I’m a software engineer and using no-code/low-code tools feel like I’m handcuffed 
Thanks for the info.
I only need the calculation to be performed when the record is opened. I’m still trying to think of how to rework what I’m doing to get the desired outcome.