如何将 SQL 查询转换为 HQL

Question

public class EmployeeUserMap {

    @ManyToOne
    @JoinColumn(name = "EMPLOYEEID", unique = true)
    protected Employee employee;

    @ManyToOne
    @JoinColumn(name="USERID")
    private User user;
}

public class RoleUserMap  {


    @ManyToOne
    @JoinColumn(name = "ROLEID")
    private Role role;


    @ManyToOne
    @JoinColumn(name = "USERID")
    private User user;


}

下面是我的 SQL 查询。

select e.id ,e.firstname from employee_user_map o
          left join role_user_map ru on ru.userid = o.userid
          left join employee e on e.id = o.employeeid
          where  ru.roleid =  (select r.id from role r  where r.code='Role_Merchant')

我尝试了 HQL 查询。

 SELECT new com.erp.core.repository.value.LookupValue(o.id,o.firstName,o.firstName) FROM EmployeeUserMap o
            LEFT JOIN o.user =
            WHERE /*@{SYSTEM_CRITERIA}*/1=1 AND (UPPER(o.firstName) LIKE UPPER(CONCAT('%',:searchParam,'%')))

Answer 1

假设您的映射正确，您应该将 hql 查询形成为：

休眠版本

  select new   com.erp.core.repository.value.LookupValue(e.id,e.firstName) 
      from EmployeeUserMap eu
         , RoleUserMap ru
         , Employee e
         , User u
         , Role r
      where  r.code ='Role_Merchant'
          and eu.user = u
          and ru.user = u
          and ru.role =r
          and eu.employee = e 

不认为你真的需要这里的子查询..

更新：对于 5.1.0+ 版本的 HIbernate，可以使用不相关的实体连接，因此在您的情况下：

  select new com.erp.core.repository.value.LookupValue(e.id,e.firstName) 
  from EmployeeUserMap o
    left join o.user u
    left join o.employee e
    left join RoleUserMap ru on ru.user.id = u.id
    left join ru.role r
  where  r.code ='Role_Merchant'