mysql> create table department ( -> -> id int primary key auto_increment, -> dep_name varchar(30), -> dep_location varchar(30) -> -> )charset utf8; Query OK, 0 rows affected (0.00 sec) mysql> create table emp ( -> -> id int primary key auto_increment, -> name varchar(30), -> age int, -> dep_id int, -> CONSTRAINT emp_dep_fk foreign key (dep_id) references department(id) -> )charset utf8; Query OK, 0 rows affected (0.00 sec) mysql> insert into emp (name, age, dep_id) values ("张三", 20, 1); Query OK, 1 row affected, 2 warnings (0.00 sec) mysql> select * from emp; +----+------+------+--------+ | id | name | age | dep_id | +----+------+------+--------+ | 1 | | 20 | 1 | +----+------+------+--------+ 1 row in set (0.00 sec)
外键没有起作用, 经查看发现:
mysql> show variables like ‘%storage_engine%‘; +------------------------+--------+ | Variable_name | Value | +------------------------+--------+ | default_storage_engine | MyISAM | | storage_engine | MyISAM | +------------------------+--------+ 2 rows in set (0.00 sec)
使用的引擎是MyISAM. 将其设置为InnoDB.
mysql> set default_storage_engine="InnoDB" -> ; Query OK, 0 rows affected (0.00 sec)
mysql> show variables like ‘%storage_engine%‘; -- 这个只是临时设置, 当数据库断开重新链接后就会变会MyISAM
+------------------------+--------+
| Variable_name | Value |
+------------------------+--------+
| default_storage_engine | InnoDB |
| storage_engine | InnoDB |
+------------------------+--------+
2 rows in set (0.00 sec)
将MySQL的引擎持久的改成InnoDB
修改My.ini: default-storage-engine=INNODB 重新数据库
C:\Users\Administrator.DESKTOP-UHUP1G8>mysql -uroot -p
Enter password: ****
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.53 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> show variables like ‘%storage_engine%‘;
+------------------------+--------+
| Variable_name | Value |
+------------------------+--------+
| default_storage_engine | InnoDB |
| storage_engine | InnoDB |
+------------------------+--------+
2 rows in set (0.00 sec)
这样在从写登录进来后也是InnoDB了
原文:https://www.cnblogs.com/exp0it/p/11625841.html