ORA-01752: cannot delete from view without exactly one key-preserved table

ORA-01752: cannot delete from view without exactly one key-preserved table

Cause: The deleted table either had no key perserved tables, had more than one key-preserved table, or the key-preserved table was an unmerged view or a table from a read-only view.

Action: Redefine the view or delete it from the underlying base tables.