HELP with Ref another table with a valid_if expression

AppSheet AppSheet Q&A
1

We have a shared environment with a shared PC that all staff use. So we have a common username that logs into Appsheet and then we have a form in a CLOCKIN table where staff select their names from a drop down list to “clock-in” and clock-out" of their shifts. All staff names are in another table STAFF which contains all the staff details.

Currently when staff go to clock-in, it references the STAFF list from another table. This returned list contains all staff but I want to only select the STAFF names that have not already clocked-in.

I recently realised that STAFF can mistakenly clock-in twice and I want to filter the reference table list to only show the STAFF names that have not already clocked-in.

2

Hello! You can use something like this

EmployeeTable[ID]
-
SELECT(
  AttendanceTable[EmployeeID],
  [DateOfAttendance] = TODAY()
)
3

For reference:

4

That setup makes sense for a shared PC. One thing I’d consider is preventing duplicate or incorrect clock-ins by recording the selected staff member, timestamp, and clock-in/clock-out status for each entry. It may also help to use the STAFF table as the single source for the dropdown so inactive or duplicate names don’t appear.