使用Hibernate Criteria从多个表中检索数据而不使用实体映射设置

Question

我的项目有问题.我正在尝试创建一个搜索功能来搜索用户表中的用户,但与此同时,我还想从另一个头像表中检索用户头像的相应" url ".我想在这两个表之间创建一个硬映射.如何使用Hibernate Criteria灵活地完成它？两个表都使用" loginID "的主键.

我有两节课:

public class User{
    private String loginID;
    private String screenname;
    ......
}
public class Avatar{
    private Integer id;
    private String loginID;
    private String url;
    .......
}

我写的:

  public List<Users> searchLogin(String keywords, int startFrom) {
        List<Users> userList = new ArrayList<Users>();
        try {
            Session session = HibernateUtil.beginTransaction();
            Criteria criteria = session.createCriteria(Users.class,"users");
            criteria.add(Restrictions.ilike("loginID", keywords, MatchMode.ANYWHERE));
            userList = criteria.list();
            if (session.isOpen()) {
                session.close();
            }
            return userList;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

多谢你们!!

Answer 1

迟到了,但对于那些真正谷歌并最终到此的人来说,它可能会有用.无需映射或使用HQL.

这是如何做:

    CriteriaBuilder builder = em.getCriteriaBuilder();
    CriteriaQuery<Tuple> criteria = builder.createTupleQuery();
    Root<EntityA> entityARoot= criteria.from(EntityA.class);
    Root<EntityB> entityBRoot = criteria.from(EntityB.class);

    //Predicates
    List<Predicate> predicates = new ArrayList<>();
    //Add the predicates you need

    //And predicates
    List<Predicate> andPredicates = new ArrayList<>();
    andPredicates.add(builder.equal(entityARoot.get("id"), entityBRoot.get("id")));
    andPredicates.add(builder.and(predicates.toArray(new Predicate[0])));

    criteria.multiselect(entityARoot, entityBRoot);
    criteria.where(andPredicates.toArray(new Predicate[0]));

    TypedQuery<Tuple> query = em.createQuery(criteria);

    List<Tuple> result = query.getResultList();

Answer 2

使用HQL

from User u,Avatar a where where u.loginID = a.loginID and u.loginID = :loginID

这将返回 [User,Avatar] 数组的列表。