ORA-01451: column to be modified to NULL cannot be modified to NULL
Cause: the column may already allow NULL values, the NOT NULL constraint is part of a primary key or check constraint.
Action: if a primary key or check constraint is enforcing the NOT NULL constraint, then drop that constraint.
Cause: the column may already allow NULL values, the NOT NULL constraint is part of a primary key or check constraint.
Action: if a primary key or check constraint is enforcing the NOT NULL constraint, then drop that constraint.
