I have a spreadsheet where I'm using the trailing set of columns as a kind of foreign key; I'm trying to throw an error if someone enters a value that doesn't exist.
I'm thinking one way to do this would be to treat the remaining columns as an array (ie: I2:2) and compare that array to the list of all names (ie: A2:A).
Is there a way to do this?
If their query capability was more sophisticated I could do something like:
SELECT I FROM I2:2 WHERE NOT EXISTS( SELECT 1 FROM A2:A WHERE A=I );