外键约束 foreign key 外键约束的要求： 父表和字表必须使用相同的存储引擎，禁止使用临时表； 数据库...
KEY`ref_num` (`ref_num`), CONSTRAINT`ref_num_ibfk_1`FOREIGNKEY(`ref_num`)REFERENCES`solution_table` (`num1`) ) ref_table有个外键约束指向表solution_table。按照字母顺序,mysqldump会先dump出ref_table。在还原过程中,就会遇到如下的错误: 1 ERROR 1215 (HY000)atline 50: Cannotaddforeignkeyconstrai...
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`mail3x`.`james_mail`, CONSTRAINT `james_mail_ibfk_1` FOREIGN KEY (`MAILBOX_ID`) REFERENCES `james_mailbox` (`MAILBOX_ID`) ON DELETE CASCADE) ...
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`Orange/pc`, CONSTRAINT `pc_ibfk_1` FOREIGN KEY (`cpumodel`) REFERENCES `parts` (`cpu`)) 四、外键的删除 这个fk_pc就是表pc的外键,用来为删除外键定义用的,如下所示: mysql> ALTER TABLE pc DROP FORE...
2017-06-09T08:09:24.559284Z 0 [Warning] InnoDB: Creating foreign key constraint system tables. 2017-06-09T08:09:25.174319Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: f3a3b10f-4cea-...
(19) NULL, PRIMARY KEY (`id`), CONSTRAINT FOREIGN KEY `FK_exam_time_exam` (`exam_id`) REFERENCES `aac_test`.`exam` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION ) ENGINE = INNODB CHARACTER SET utf8 COLLATE utf8_general_ci; ALTER TABLE exam_time CHANGE COLUMN exam_id examId BIG...
mysql> create table `Table2`(c1 int primary key, c2 int) engine=InnoDB; Query OK, 0 rows affected (0.04 sec) mysql> alter table `Table2` add constraint fk1 foreign key(c2) references `Table1`(c1); Query OK, 0 rows affected (0.07 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql...
前提是你的电脑中配置了MySQL的环境变量,某则需要在MySQL的安装目录中找到mysqldump 程序入口。 2022-08-01_143245.png 但是当我在Java代码中使用Runtime.getRuntime().exec("cmd")执行这个SQL语句时,process.waitFor()返回了6,是一个错误的结果。