Using values from portal lines in a calculation
Hello. I'm trying to do something pretty straightforward and am very close but final step alludes me. It involves calculations using data found in a portal and is related to posts Calculations with portal data. and Using values from portal lines in a calculation.
I am tracking attendance and want to determine whether a student was present on a given day. I have two tables, a Students list and an Attendance_Log:
Table 1 (parent), Students, with the following fields:
- Student ID
Table 2 (child), Attendance_Log, with the following fields:
- Student ID
Attempt 1: Using a portal
I successfully created a portal on the parent table, and can see
all the dates that a student attended class. But how does one go
about searching inside the portal for a specific date?
Attempt 2: Using a calculation
Alternately, I tried adding a calculation field in the parent
table to determine whether an entry exists for each student for a
particular date. Conceptually, the calculation would be
Students::Sept1? = If ( Attendance_Log::Date ="Sept 1" ; yes ; no )
but this calculation fails because the result only represents the
result of the search of the last matching record, and not of all
the matching records found in the child table.
Knowing how to work with the portal data would open many doors. Any help is much appreciated.