mysql> insert into region_zip (region_id,zip_id) values (1, 294761);
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`cf2_dev/region_zip`, CONSTRAINT `region_zip_FK_2` FOREIGN KEY (`zip_id`) REFERENCES `zip` (`id`))
mysql> select id from zip where id = 294761;
+--------+
| id     |
+--------+
| 294761 |
+--------+
1 row in set (0.00 sec)