Modify Table Insert Calculated Column

Please tell me the syntax for inserting a calculated column into an Oracle 10g database. The SQL Server ALTER TABLE code won't work. A simple example:

ALTER TABLE Rentals

     ADD TotalRentals AS TotalRentals + RentalQuantity;

I've spent a couple hours searching the doc & Google and I'm coming up emty handed. This should be simple!

Thanks Received on Fri Apr 21 2006 - 12:02:06 CDT