Hibernate中many to one 生成的sql语句
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悬赏园豆：10
[待解决问题]
当用<mang to one >元素和<one to one>元素组合实现双向一对一的关联时为什么生成的是外联结语句，而<mang to one >元素和Set元素的<one to many>组合实现双向一对多的关联却没有生成表连接语句。
双向一对一：
@Testpublicvoid testGet(){//1. 默认情况下对关联属性使用懒加载Department dept =(Department) session.get(Department.class,1);System.out.println(dept.getDeptName()); //2. 所以会出现懒加载异常的问题. session.close();Manager mgr = dept.getMgr();System.out.println(mgr.getClass());System.out.println(mgr.getMgrName()); //3. 查询 Manager 对象的连接条件应该是 dept.manager_id = mgr.manager_id//而不应该是 dept.dept_id = mgr.manager_id mgr = dept.getMgr();System.out.println(mgr.getMgrName()); }通过dept查询关联的mgr：
第一步：查询出mgr
select manager0_.MGR_ID as MGR_ID1_2_1_, manager0_.MGR_NAME as MGR_NAME2_2_1_, department1_.DEPT_ID as DEPT_ID1_1_0_, department1_.DEPT_NAME as DEPT_NAM2_1_0_, department1_.MGR_ID as MGR_ID3_1_0_ from MANAGERS manager0_ left outer join DEPARTMENTS department1_ on manager0_.MGR_ID=department1_.MGR_ID where manager0_.MGR_ID=?第二步：查询出mgr关联的dept
select department0_.DEPT_ID as DEPT_ID1_1_0_, department0_.DEPT_NAME as DEPT_NAM2_1_0_, department0_.MGR_ID as MGR_ID3_1_0_ from DEPARTMENTS department0_ where department0_.MGR_ID=?双向一对n,没有表连接语句
