We are trying to do a compute for when a date is missing from our oracle table. There seems to be an issue between running the same code in a "where" statement than in an "if" statement.

When I run

IF DATE_TAKEN NE MISSING THEN 0 ELSE 1; 

I get the error
(FOC280) COMPARISON BETWEEN COMPUTATIONAL AND ALPHA VALUES IS NOT ALLOWED

but if I run

WHERE DATE_TAKEN NE MISSING; 

there are no errors and everyone is happy. Is there some hidden reason that my code is not working?

No guarantees that my memory is correct, but I seem to think that the phrase

IS-NOT MISSING

used to work.