MySQL error code
MySQL error 1557
MySQL server error 1557 is ER_FOREIGN_DUPLICATE_KEY_OLD_UNUSED, reported with SQLSTATE 23000.
Upholding foreign key constraints for table '%s', entry '%s', key %d would lead to a duplicate entry
| Error | 1557 |
|---|---|
| Name | ER_FOREIGN_DUPLICATE_KEY_OLD_UNUSED |
| SQLSTATE | 23000 |
| Group | Server errors |
In other databases
Source: MySQL 8.4 Error Reference