насильно удалить ряд в MySQL, который имеет ссылки
SET FOREIGN_KEY_CHECKS=0;
DELETE FROM forum WHERE Owner_Id = 1 ORDER BY nright;
SET FOREIGN_KEY_CHECKS=1;
Lucky Lark
SET FOREIGN_KEY_CHECKS=0;
DELETE FROM forum WHERE Owner_Id = 1 ORDER BY nright;
SET FOREIGN_KEY_CHECKS=1;