小编Dmi*_*try的帖子

很多时候我在我的实体中使用@Formula.但总是这是一个简单的查询或带参数的存储过程,我可以从表中提取.现在我需要从相关对象中使用一些属性.但是当我尝试从DB获取对象时,我看到异常.请看下面的例子

@Entity
@Table(name = "MINISTRY")
public class Ministry {

    @Id
    @Column(name = "ID")
    private Long id;

    @Column(name = "NAME")
    private String name;

    // unnecessary code

}

@Entity
@Table(name = "DEPARTMENT")
public class Department {

    @Id
    @Column(name = "ID")
    private Long id;

    @Column(name = "DEP_NAME")
    private String departmentName;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "MINISTRY_ID")
    private Ministry ministry;

    // unnecessary code
}

@Entity
@Table(name = "EMPLOYEE")
public class Employee {

    @Id
    @Column(name = "ID")
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = …