I am writing a payroll program. I need to display on a check stub the
current amount and the year to date amount for all of the deductions.
I would like to do something like

SELECT t.Description, d.CurrentAmount, sp.YTDAmount
FROM Detail d
INNER JOIN PayType t ON t.hKey = d.hPayType
INNER JOIN sp_YTDAmt(d.hCheck, d.hPayType) sp ON 1=1

but I am not sure about what to put in the ON clause of the inner join
to the stored procedure. I reviewed the section in The Firebird Book
on selectable stored procedures and I have searched the newsgroup but
I am not finding anything that touches on this directly.

Is it just that you cannot join to a stored procedure? It appears
that I can rewrite this using a stored procedure to enclose a cursor
that first gets the Description and CurrentAmount and then calls
another stored procedure to get the YTDAmount. Is this the right
approach?

Thanks for your help.

-Jack Rodenhi