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>
運(yùn)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 |
+---------------+----------------------------------
---------------------------------------------------
經(jīng)過(guò)一天多的反復(fù)研究,發(fā)現(xiàn)是ENGINE=MyISAM的問(wèn)題。
原因:
關(guān)聯(lián)的兩個(gè)表中,一個(gè)或者兩個(gè)表是MyISAM引擎的表。若想要使用外鍵約束,表必須是InnoDB引擎(實(shí)際上,如果兩個(gè)表都是MyISAM 引擎的,這個(gè)錯(cuò)誤根本不會(huì)發(fā)生,但也不會(huì)產(chǎn)生外鍵,只會(huì)建立索引)你需要檢查表的引擎類(lèi)型。
具體的幾種不能生成外鍵的原因可以看一下:http://blog.csdn.net/wangpeng047/article/details/19624351
查看數(shù)據(jù)庫(kù)默認(rèn)的引擎:
--查看當(dāng)前數(shù)據(jù)庫(kù)支持的引擎列表
show engines;
--查看當(dāng)前的默認(rèn)引擎
show variables like '%storage_engine%';
--修改表引擎,這里不需要用到
alter table table_name engine=innodb;

image.png
這里手動(dòng)修改是不現(xiàn)實(shí)的,配置hibernate.cfg.xml:
<!-- 方言 -->
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
這里mysql5.0以上是org.hibernate.dialect.MySQL5InnoDBDialect,以下就去掉5
然后刪庫(kù),重新自動(dòng)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