SQL和Hibernate使用连接表获取项目列表

Question

I am trying to get this logic from the database :

Get Roles by their names, and only roles of users specified by userid entered on a form.

Tables :

Roles [ idrole, role]
User [iduser, ...]
User_Roles [iduser, idrole]

I did this in SQL like this :

Query query = getSessionFactory().getCurrentSession().createSQLQuery("SELECT role FROM roles WHERE idrole IN (SELECT idrole FROM User_Roles WHERE iduser = :Iduser)").setParameter("Iduser", iduser);

but this returns only roles, not their ids which would be needed later to do a direct update of user roles

when I do this :

Query query = getSessionFactory().getCurrentSession().createSQLQuery("SELECT role, idrole FROM roles WHERE idrole IN (SELECT idrole FROM User_Roles WHERE iduser = :Iduser)").setParameter("Iduser", iduser);

It returns this : [[Ljava.lang.Object;@1e9b4920, [Ljava.lang.Object;@2e0670e5]

And can't get how to show the Object contained data, I tried with hibernate like this :

Query query = getSessionFactory().getCurrentSession().createQuery("from Role r INNER JOIN r.userRoles a where a.iduser  = :Iduser").setParameter("Iduser", iduser);

It returns something like [User Object, Roles Object] which driven me to try it using an SQLQuery, but no chance ..

Answer 1

I think you can do like this:

Query query = getSessionFactory().getCurrentSession().createSQLQuery("FROM roles WHERE idrole IN (SELECT idrole FROM User_Roles WHERE iduser = :Iduser)").setParameter("Iduser", iduser);

and get it like:

List<Roles> all = (List<Roles>)query.list();

Then you can do your business by looping the list

Hope this help!