Hibernate中单向一对多删除级联数据问题

public static void main(String[] args) {

// test();
// test1();
// test2();
// test3();
// test4();

// test5();

// 测试one2many 单向
test6();
// 测试单向 维护关系 delete删除操作
// test7();
// 测试单向 维护关系 delete更新操作
// test8();

}

private static void test8() {
// 获得 session 开启事务
SessionFactory sessionFactory = new Configuration().configure()
.buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();

// 新建 一方数据 设置ID 为主键值
PersonInfo personinfo = new PersonInfo();
personinfo.setPerId("4028e5734cf9ddc8014cf9ddc9860001");
// 删除该对象 并未执行删除多方数据
session.delete(personinfo);
session.flush();
// 提交事务
session.getTransaction().commit();
// 关闭session
session.close();

}

private static void test7() {
// 获得 session 开启事务
SessionFactory sessionFactory = new Configuration().configure()
.buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();
// 载入该对象
PersonInfo personinfo = (PersonInfo) session.load(PersonInfo.class,
"4028e5734cf9d163014cf9d164fc0001");
// 取出多方数据集合
Set<One2Many> set = personinfo.getOne2many();
Iterator<One2Many> iterator = set.iterator();
// 迭代输出 多方 主键值
while (iterator.hasNext()) {
System.out.println(iterator.next().getTest4());
}
// 删除一方数据
session.delete(personinfo);
// 提交事务
session.getTransaction().commit();
// 关闭session
session.close();
}

private static void test6() {

// 获得 session 开启事务
SessionFactory sessionFactory = new Configuration().configure()
.buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();

// 创建一方 对象值
PersonInfo personinfo = new PersonInfo();
personinfo.setPerName("单向one2many");

// 创建多方数据并存入集合
One2Many o = new One2Many();
o.setTest2("单向1");
One2Many o2 = new One2Many();
o2.setTest2("单向2");
One2Many o3 = new One2Many();
o3.setTest2("单向3");
HashSet<One2Many> set = new HashSet<One2Many>();
set.add(o);
set.add(o2);
set.add(o3);
// 将数据绑定一方数据
personinfo.setOne2many(set);
// 保存一方数据
session.save(personinfo);
// 提交事务
session.getTransaction().commit();
// 关闭session
session.close();

}

方法7与方法8的 执行结果是不一样的。

方法8 运行结果：
Hibernate: update Test set b=null where b=?
Hibernate: update one2many set test3=null where test3=?
Hibernate: delete from personinfo where perId=?
执行的是更新外键值为null

方法7执行结果：
Hibernate: select personinfo0_.perId as perId0_2_, personinfo0_.perName as perName0_2_, personinfo0_.perSex as perSex0_2_, personinfo0_.perAge as perAge0_2_, personinfo0_.perPhone as perPhone0_2_, personinfo0_.PerAddress as PerAddress0_2_, personinfo0_.perJob as perJob0_2_, personinfo0_.perEntryTime as perEntry8_0_2_, personinfo0_.PerDeparturetime as PerDepar9_0_2_, personinfo0_.perCreateDate as perCrea10_0_2_, personinfo0_.perLastModifyDate as perLast11_0_2_, mtwo2many1_.e as e4_, mtwo2many1_.a as a4_, mtwo2many1_.a as a4_0_, mtwo2many1_.b as b4_0_, mtwo2many1_.c as c4_0_, mtwo2many1_.d as d4_0_, mtwo2many1_.e as e4_0_, one2many2_.test3 as test4_5_, one2many2_.test4 as test1_5_, one2many2_.test4 as test1_6_1_, one2many2_.test1 as test2_6_1_, one2many2_.test2 as test3_6_1_, one2many2_.test3 as test4_6_1_ from personinfo personinfo0_ left outer join Test2 mtwo2many1_ on personinfo0_.perId=mtwo2many1_.e left outer join one2many one2many2_ on personinfo0_.perId=one2many2_.test3 where personinfo0_.perId=?
Hibernate: select one2one0_.test4 as test1_1_0_, one2one0_.test1 as test2_1_0_, one2one0_.test2 as test3_1_0_, one2one0_.test3 as test4_1_0_ from one2one one2one0_ where one2one0_.test4=?
4028e5734cf9e355014cf9e356720003
4028e5734cf9e355014cf9e356720004
4028e5734cf9e355014cf9e356720002
Hibernate: select mone2many0_.b as b1_, mone2many0_.a as a1_, mone2many0_.a as a3_0_, mone2many0_.b as b3_0_, mone2many0_.c as c3_0_ from Test mone2many0_ where mone2many0_.b=?
Hibernate: update one2many set test3=null where test3=?
Hibernate: delete from one2many where test4=?
Hibernate: delete from one2many where test4=?
Hibernate: delete from one2many where test4=?
Hibernate: delete from personinfo where perId=?

执行delete 是删除操作

personinfo
key是指定 字段test3作为 表one2many的外键 并且值是 perinfo的主键值

<set fetch="join" name="one2many" cascade="all">
<key column="test3"></key>
<one-to-many class="com.yjm.pojo.person.One2Many" />
</set>

双向关联 需要在 one2many里配置

<many-to-one name="personinfo" class="com.yjm.pojo.person.PersonInfo" column="test3"></many-to-one>

注意在 personinfo里指定的外键 test3 不需要在 one2many 配置 单向一对多的 可以在one2many里配置

<hibernate-mapping>
<class name="com.yjm.pojo.person.One2Many" table="one2many" lazy="true">
<id name="test4" type="java.lang.String">
<generator class="uuid" />
</id>
<property name="test1" type="java.lang.String" />
<property name="test2" type="java.lang.String" />
<many-to-one name="personinfo" class="com.yjm.pojo.person.PersonInfo" column="test3"></many-to-one>
</class>
</hibernate-mapping>