hibernate 配置如下：
<?xml version="1.0" encoding="UTF-8"?>
<!-- Course.hbm.xml -->
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="cc.sirius.bean">
<class name="Person">
<id name="id" column="personId">
<generator class="native"/>
</id>
<set name="addresses" table="PersonAddress">
<key column="personId"/>
<many-to-many column="addressId"
class="Address"/>
</set>
</class>
</hibernate-mapping>
<?xml version="1.0" encoding="UTF-8"?>
<!-- Course.hbm.xml -->
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="cc.sirius.bean">
<class name="Address">
<id name="id" column="addressId">
<generator class="native"/>
</id>
<set name="people" inverse="true" table="PersonAddress">
<key column="addressId"/>
<many-to-many column="personId"
class="Person"/>
</set>
</class
>
</hibernate-mapping>
运行后查看表：
mysql> show create table PersonAddress;
+---------------+----------------------------------
---------------------------------------------------
---------------------------------------------------
---------------------------------------------------
| Table | Create Table
+---------------+----------------------------------
---------------------------------------------------
---------------------------------------------------
---------------------------------------------------
| PersonAddress | CREATE TABLE `personaddress` (
`addressId` int(11) NOT NULL,
`personId` bigint(20) NOT NULL,
PRIMARY KEY (`personId`,`addressId`),
KEY `FKA81B4EBF34EDEFEE` (`personId`),
KEY `FKA81B4EBF4E1D97BA` (`addressId`),
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
+---------------+----------------------------------
---------------------------------------------------
经过一天多的反复研究，发现是ENGINE=MyISAM的问题。
原因：
关联的两个表中，一个或者两个表是MyISAM引擎的表。若想要使用外键约束，表必须是InnoDB引擎（实际上，如果两个表都是MyISAM 引擎的，这个错误根本不会发生，但也不会产生外键，只会建立索引）你需要检查表的引擎类型。
具体的几种不能生成外键的原因可以看一下：http://blog.csdn.net/wangpeng047/article/details/19624351
查看数据库默认的引擎：
--查看当前数据库支持的引擎列表
show engines;
--查看当前的默认引擎
show variables like '%storage_engine%';
--修改表引擎,这里不需要用到
alter table table_name engine=innodb;
image.png
这里手动修改是不现实的，配置hibernate.cfg.xml：
<!-- 方言 -->
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
这里mysql5.0以上是org.hibernate.dialect.MySQL5InnoDBDialect,以下就去掉5
然后删库，重新自动生成：
---------------------------------------------------------------+
| personaddress | CREATE TABLE `personaddress` (
`addressId` int(11) NOT NULL,
`personId` bigint(20) NOT NULL,
PRIMARY KEY (`personId`,`addressId`),
KEY `FKA81B4EBF34EDEFEE` (`personId`),
KEY `FKA81B4EBF4E1D97BA` (`addressId`),
CONSTRAINT `FKA81B4EBF34EDEFEE` FOREIGN KEY (`personId`) REFERENCES `person` (
`personId`),
CONSTRAINT `FKA81B4EBF4E1D97BA` FOREIGN KEY (`addressId`) REFERENCES `address`
(`addressId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+---------------+---------------------------------------------------------------
完成
