I have a table XYZ with accnt id as primary key and a maturity date column apart from 20 other columns. My requirement is that i need to to take a backup of this maturity date column. So i will create a separate table ABC by accnt id and maturity date from XYZ table. Now due to some application requirement i need to update the maturity date column with a specific value. After the work of application is over i need to revert the maturity date column to its original values picking data from ABC table.Kindly help how i can achieve this using a query.