Hiberante内部联接给出了“联接所需的路径”异常

Question

我有以下实体，

    @Entity
    @Table(name = "person")
    public class Person implements Serializable {

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id")
        private Long id;

        // Other fields 
    }

     @Entity
        @Table(name = "agreement")
        public class Agreement implements Serializable {

            private static final long serialVersionUID = 15L;

            @Id
            @GeneratedValue(strategy = GenerationType.IDENTITY)
            @Column(name = "id")
            private Long id;

            @ManyToOne
            @JoinColumn(name = "person_id", nullable = false)
            private Person person;

            @ManyToOne
            @JoinColumn(name = "company_id", nullable = false)
            private Company company;

        }

    @Entity
    @Table(name = "company")
    public class Company implements Serializable {

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id")
        private Long id;

        @Column(name = "name", length = 100)
        private String name;
    }

我需要获得所有与公司签订公司ID 45协议的人员。下面是我编写的用于获取详细信息的本机查询。

SELECT distinct p.* ROM person p INNER JOIN agreement a ON a.person_id = p.id where a.company_id = 45;

但我被告知将其转换为JPA实体查询。我想出了以下内容，

SELECT distinct p  FROM Person p INNER JOIN Agreement a WHERE a.person = p AND a.company.id = 45;

但这给了我以下例外，

原因：org.hibernate.hql.internal.ast。QuerySyntaxException:连接路径应为！[在org.hibernate.hql.internal.ast.QuerySyntaxException.convert（QuerySyntaxException.java:74）的org.hibernate.hql.internal.ast.ErrorCounter.throwQueryException（ErrorCounter.java:91）的org.hibernates.hql.内部连接协议a中选择不同的p，其中a.Person=p和a.company.id=45]org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile（QueryTranslaterImpl.java:190）位于org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile（QuerytranslaterImpL.java:142），位于org.hibernate.engine.query.spi.HQLQueryPlan.（hqlQuery.java:115）位于org.hibernate.engine.QLQueryPlan（QueryPlanCache.java:150）在org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan（AbstractSessionImpl.java:302），在org.hibernate.internal.AbstractSessionImpl.createQuery（AbstractionSessionImpL.java:240）在org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery（AbtractEntityManager.java:305）

有人可以帮助我解决我在查询中做错了什么吗？

Answer 1

JPA在HQL语句中使用路径，从一个实体到另一个实体相关联，并且由于它没有找到任何路径，因此它正在抱怨。您可以尝试以下查询。

SELECT distinct p FROM Agreement a JOIN a.person p WHERE a.company.id = 45;