我正在为下表寻找合适的JPQL查询，以便它可以在Java代码中工作，而不应该是本地查询

Question

下面是我无法对其进行正确的JPQL查询的表模式

  Mobile table     | hardware table       |  releases table
  --------------------------------------------------------------
  id pk            |   id  pk            | id  pk
  name varchar         size  varchar       launchdate varchar
  hardware_id fk   |   pdname varchar    | tally  varchar
  releases_id fk   |                     | 

 i have tried all below query's in my code but it all gives error for:
  //String qry="Select m.name,h.size,h.pdname from com.example.users.Mobile m, 
   com.example.users.entities.Hardware h where m.hardware_id=h.id ";


    //String qry="Select m from Mobile m inner join fetch m.hardware h where m.hardware_id=h.id";

    //String qry = "SELECT m FROM Mobile m JOIN m.hardware_id h WHERE m.hardware_id = h.id";

    String qry="select m.name from mobile m,hardware h where m.hardware_id=h.id";


   System.out.println("in entity manager Query is "+ qry);

    Query query = entityManager.createQuery(qry);

    return query.getResultList();

错误：org.hibernate.hql.internal.ast.QuerySyntaxException：手机未映射

Answer 1

Mobile实体中是否有这样的属性？

    @ManyToOne(optional = false)
    @JoinColumn(name = "hardware_id")
    private Hardware hardware;