为什么 mygroup
上的 TRUNCATE 不起作用?
即使我有 ON DELETE CASCADE SET
我得到:
ERROR 1701 (42000): Cannot truncate a table referenced in a foreign key constraint (
mytest
.instance
, CONSTRAINTinstance_ibfk_1
FOREIGN KEY (GroupID
) REFERENCESmytest
.mygroup
(ID
))
drop database mytest;
create database mytest;
use mytest;
CREATE TABLE mygroup (
ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
) ENGINE=InnoDB;
CREATE TABLE instance (
ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
GroupID INT NOT NULL,
DateTime DATETIME DEFAULT NULL,
FOREIGN KEY (GroupID) REFERENCES mygroup(ID) ON DELETE CASCADE,
UNIQUE(GroupID)
) ENGINE=InnoDB;
最佳答案
是的,你可以:
SET FOREIGN_KEY_CHECKS = 0;
TRUNCATE table1;
TRUNCATE table2;
SET FOREIGN_KEY_CHECKS = 1;
使用这些语句,您可能会将不遵守 FOREIGN KEY
约束的行放入表中。
https://stackoverflow.com/questions/5452760/