I have a table a with a list of id's, and a user-defined function foo(id) that takes the id and returns a VARCHAR(20). What I am trying to do is: SELECT id, foo(id) AS 'text field' FROM a However, instead of calling the function for each ID number, like I desired, the text comes back the same for every row. I have tested the foo() function manually with the returned ID's and it does not have that problem, so I realize I must not understand something about the evaluation of the query.