4000 hibernate框架多对多-级联保存（十八）

一、多对多级联保存

多对多级联保存，只要在上一篇的基础上对User.hbm.xml配置稍作修改

1.1 配置

多对多级联的时候，一方配置inverser，另一方就配置cascade

1.2 测试程序

@Test
public void run2() {
Session session = HibernateUtils.getCurrentSession();
Transaction tx = session.beginTransaction();

// 模拟多对多，双向的关联
// 创建用户
User u1 = new User();
u1.setUsername("zhangsan");
User u2 = new User();
u2.setUsername("lisi");

// 创建角色
Role r1 = new Role();
r1.setRname("manager");
Role r2 = new Role();
r2.setRname("actor");

// 关联
u1.getRoles().add(r1);
u1.getRoles().add(r2);
u2.getRoles().add(r1);

session.save(u1);
session.save(u2);

tx.commit();
}

1.3 运行结果

截图就不贴了（反正和上一篇都一样），看sql吧

log4j:WARN No appenders could be found for logger (org.jboss.logging).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Hibernate:
insert
into
sys_user
(username, password)
values
(?, ?)
Hibernate:
insert
into
sys_role
(rname)
values
(?)
Hibernate:
insert
into
sys_role
(rname)
values
(?)
Hibernate:
insert
into
sys_user
(username, password)
values
(?, ?)
Hibernate:
insert
into
sys_user_role
(uid, rid)
values
(?, ?)
Hibernate:
insert
into
sys_user_role
(uid, rid)
values
(?, ?)
Hibernate:
insert
into
sys_user_role
(uid, rid)
values
(?, ?)

二、操作中间表-删除

想要操作中间表，我们只需要操作javabean中的集合

2.1 测试程序

/**
* 现在：zhangsan用户，有2个角色，manager和actor
* 让zhangsan没有actor角色
*/
@Test
public void run3() {
Session session = HibernateUtils.getCurrentSession();
Transaction tx = session.beginTransaction();

// 查询zhangsan用户
User u1 = session.get(User.class, 1L);
// 查询角色
Role r2 = session.get(Role.class, 2L);
u1.getRoles().remove(r2);

tx.commit();
}

2.2 运行结果

看sql：

log4j:WARN No appenders could be found for logger (org.jboss.logging).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Hibernate:
select
user0_.uid as uid1_1_0_,
user0_.username as username2_1_0_,
user0_.password as password3_1_0_
from
sys_user user0_
where
user0_.uid=?
Hibernate:
select
role0_.rid as rid1_0_0_,
role0_.rname as rname2_0_0_
from
sys_role role0_
where
role0_.rid=?
Hibernate:
select
roles0_.uid as uid1_2_0_,
roles0_.rid as rid2_2_0_,
role1_.rid as rid1_0_1_,
role1_.rname as rname2_0_1_
from
sys_user_role roles0_
inner join
sys_role role1_
on roles0_.rid=role1_.rid
where
roles0_.uid=?
Hibernate:
delete
from
sys_user_role
where
uid=?
and rid=?

三、操作中间表-添加

3.1 测试程序

/**
* 现在：zhangsan用户，有1个角色，manager
* 让zhangsan添加actor角色
*/
@Test
public void run4() {
Session session = HibernateUtils.getCurrentSession();
Transaction tx = session.beginTransaction();

// 查询zhangsan用户
User u1 = session.get(User.class, 1L);
// 查询角色
Role r2 = session.get(Role.class, 2L);
u1.getRoles().add(r2);

tx.commit();
}

3.2 运行结果

看sql：

log4j:WARN No appenders could be found for logger (org.jboss.logging).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Hibernate:
select
user0_.uid as uid1_1_0_,
user0_.username as username2_1_0_,
user0_.password as password3_1_0_
from
sys_user user0_
where
user0_.uid=?
Hibernate:
select
role0_.rid as rid1_0_0_,
role0_.rname as rname2_0_0_
from
sys_role role0_
where
role0_.rid=?
Hibernate:
select
roles0_.uid as uid1_2_0_,
roles0_.rid as rid2_2_0_,
role1_.rid as rid1_0_1_,
role1_.rname as rname2_0_1_
from
sys_user_role roles0_
inner join
sys_role role1_
on roles0_.rid=role1_.rid
where
roles0_.uid=?
Hibernate:
insert
into
sys_user_role
(uid, rid)
values
(?, ?)

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