Function returning boolean fails on “expression is of wrong type”

Question

I am using oracle 11g and I just cant under stand where my problem is. I have made much more difficult stuff but I fail in this simple thing for the last 5 hr :

Thi

Answer 1

Your function returns a boolean. This datatype is known to PL/SQL, but you are using a SQL query. SQL doesn't know how to handle booleans and says "expression is of wrong type".

Regards,
Rob.