ORA-00001: unique constraint (string.string) violated

ORA-00001: unique constraint (string.string) violated

Cause: An UPDATE or INSERT statement attempted to insert a duplicate key.  For Trusted Oracle configured in DBMS MAC mode, you may see this message if a duplicate entry exists at a different level.

Action: Either remove the unique restriction or do not insert the key.

The options to resolve this Oracle error are:

1. Drop the unique constraint
2. Change the constraint to allow duplicate values
3. Modify your SQL so that a duplicate value is not created

If you are not sure which unique constraint was violated, you can run the following SQL:

select distinct table_name
from all_indexes
where index_name = 'CONSTRAINT_NAME';

In our example (see picture above), our constraint name would be SYS_C002459 and we would execute the following SQL:

select distinct table_name
from all_indexes
where index_name = 'SYS_C002459';

This would return the name of the table whose unique constraint we violated.