此 HQL 会导致非常有用的“命名查询错误”消息
"FROM courseform c WHERE c.application.application IN
(SELECT a.application FROM application a WHERE a.applicant=: applicant)"
CourseForm 与应用程序具有 OneToOne 单向关系(如果有帮助,这可能是双向的)。反过来,应用程序与申请人具有相同的单向 OneToOne 关系。一个申请人可以有多个申请。
以下是(删节的)定义
课程表
@Entity
@NamedQueries({
@NamedQuery(name = "CourseForm.findByApplicant",
query = "FROM courseform c WHERE c.application.application IN
(SELECT a.application FROM application a WHERE a.applicant=: applicant)") })
public class CourseForm implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
long id;
@Enumerated(EnumType.STRING)
private Career career;
private String academicPlan;
private String courseName;
@Enumerated(EnumType.STRING)
private ModeOfAttendance modeOfAttendance;
@OneToOne
@JoinColumn(name = "application_fk")
private Application application;
...
}
应用
@Entity
public class Application implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
long applicationNumber;
@OneToOne
@JoinColumn(name = "applicant_fk")
private Applicant applicant;
@Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDateTime")
private LocalDateTime lastUpdate = LocalDateTime.now();
@Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDateTime")
private LocalDateTime submitted = null;
public Application() {
}
申请人
@Entity
@NamedQueries({ @NamedQuery(name = "Applicant.findByApplicantID",
query = "FROM Applicant a WHERE a.applicantID= :applicantID") })
public class Applicant implements Serializable {
private static final long serialVersionUID = -7210042752148566673L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
long id;
private String applicantID;
Applicant() {
}