How to fix the Oracle error ORA-01451: column to be modified to NULL cannot be modified to NULL?

In this post, you’ll learn more about the Oracle ErrorORA-01451: column to be modified to NULL cannot be modified to NULL with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-01451: column to be modified to NULL cannot be modified to NULL

Reason for the Error ORA-01451: column to be modified to NULL cannot be modified to NULL

the column may already allow NULL values, the NOT NULL constraint is part of a primary key or check constraint.

How to fix the Error ORA-01451: column to be modified to NULL cannot be modified to NULL ?

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

if a primary key or check constraint is enforcing the NOT NULL constraint, then drop that constraint.