Application Express :: How To Create A Display Field In Tabular Form

I am stuck at point.

using apex 4.1, created tabular form for inserting values from customer with a simple query

table name : customer
select
USER_ID ,
USERNAME,
PASSWORD,
STATUS,
PRODUCT_ID
from CUSTOMER

I WANT TO FETCH THE NAME OF PRODUCT FROM ANOTHER TABLE NAME PRODUCT_NAME, I WANT THAT WITH TABULAR FORM COULMN OF PRODUCT NAME IS ALSO DISPLAYED, HOW I DID THAT ? JUST WANT TO ADD COLUMN FROM ANOTHER TABLE IN TABULAR FORM.

WHEN I ADD TABLE NAME IN FIRST QUERY IT IS NOT WORKING GIVING ERROR ABOUT NOT JOINING THE TABLE