How to fix the Oracle error ORA-12999: cannot DROP or SET UNUSED a column that has been set unused?

In this post, you’ll learn more about the Oracle ErrorORA-12999: cannot DROP or SET UNUSED a column that has been set unused with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-12999: cannot DROP or SET UNUSED a column that has been set unused

Reason for the Error ORA-12999: cannot DROP or SET UNUSED a column that has been set unused

An attempt was made to DROP or SET UNUSED a column that has already been ‘set unused’.

How to fix the Error ORA-12999: cannot DROP or SET UNUSED a column that has been set unused ?

You can fix this error in Oracle by following the below steps

Use the DROP UNUSED COLUMNS option to remove the column.