Hibernate實體類的操作

2019-11-08 02:23:07

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添加

調用session里面save()方法

User user = new User();user.setUsername("Rose");user.setPassWord("123456");user.setAddress("廣東廣州");session.save(user);

查詢

根據id查詢,調用get(Class,int)方法

User tuser = session.get(User.class, 1);System.out.PRintln(tuser.toString());-- hibernate底層的實現Hibernate: select user0_.uid as uid1_0_0_, user0_.username as username2_0_0_, user0_.password as password3_0_0_, user0_.address as address4_0_0_ from t_user user0_ where user0_.uid=?-- 運行查詢結果User [uid=1, username=Jeff, password=123456, address=廣東茂名]

修改操作

先查詢，再修改

User tuser = session.get(User.class, 2);tuser.setUsername("李白");session.update(tuser); -- 底層實現Hibernate: select user0_.uid as uid1_0_0_, user0_.username as username2_0_0_, user0_.password as password3_0_0_, user0_.address as address4_0_0_ from t_user user0_ where user0_.uid=?Hibernate: update t_user set username=?, password=?, address=? where uid=?

刪除

//1. 方式一 User tuser = session.get(User.class, 1); session.delete(tuser);//2. 方式二(少用) User u = new User(); u.setUid(1); session.delete(u);

saveOrUpdate()方法的使用

此方法根據實體類的狀態選擇添加或修改//1. 瞬時態，添加User uu = new User();uu.setUsername("jack");uu.setAddress("廣州");uu.setPassword("123");session.saveOrUpdate(uu);//托管態，修改//根據實體類的id進行修改，若表中沒有相關的id,則不會修改也不會添加User uu = new User();uu.setUid(1);uu.setUsername("jack");uu.setAddress("廣州");uu.setPassword("123");session.saveOrUpdate(uu);//持久態，修改User uu = session.get(User.class,1);uu.setUsername("jack");session.saveOrUpdate(uu);

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