Hi, I am using Application Express 20.1.0.00.13. I have a table CITY(id, name). And an IG based on table PATIENT(id, name, city_id, ......). I added a column to the IG through right clicking the IG> Create Column. The column is named CITY. The column should retrieve the name of the city depending on the CITY_ID. CITY_ID column has it's static value assigned with the same name CITY_ID. The source of CITY column is SQL EXPRESSION = (select name from city where id = :CITY_ID). But it retrieves null. Where does the problem reside?