具有多级连接的Hibernate Criteria

Question

我有3个与@OneToMany关系的链接类

Luce.class

public class Luce implements java.io.Serializable{

    private Client client;
}

Client.class

public class Client implements java.io.Serializable{

        private Server server;
    }

Server.class

public class Server implements java.io.Serializable{

        private Piano Piano;
    }

我需要从指定的钢琴中获取Luce列表。 因此，在我的DAO接口的实现中，我试图执行以下操作：

Criteria criteria = createEntityCriteria();
        criteria.createAlias("client", "c");
        criteria.createAlias("server", "s");
        criteria.add(Restrictions.eq("c.s.piano", piano);

但是我得到了例外

org.hibernate.QueryException: could not resolve property: server of: it.besmart.models.Luce

Answer 1

You try to create an alias of the property server on Luce so it won't work.

Criteria criteria = createEntityCriteria();
    criteria.createAlias("client", "c");
    criteria.createAlias("c.server", "s");
    criteria.add(Restrictions.eq("s.piano", piano);