How to fix the Oracle error NID-00139: Mismatched dbname for datafile string, expected string, found string?

In this post, you’ll learn more about the Oracle ErrorNID-00139: Mismatched dbname for datafile string, expected string, found string with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

NID-00139: Mismatched dbname for datafile string, expected string, found string

Reason for the Error NID-00139: Mismatched dbname for datafile string, expected string, found string

The dbname of the datafile does not match the ‘old’ dbname or the ‘new’ dbname.

How to fix the Error NID-00139: Mismatched dbname for datafile string, expected string, found string ?

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

Verify that this datafile belongs to the database. You may need to restore a backup of the datafile.