java - 命名查询子选择中的 HQL 错误

Question

此 HQL 会产生非常有用的“命名查询中的错误”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(如果有帮助的话，可以将其设为双向关系)。反过来，应用程序与申请人具有相同的单向一对一关系。一个申请人可以有多个申请。

这是(删节的)定义

类(class)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;
...
}

申请

@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() {
    }

Answer 1

好吧，根据马克的说法，正确答案是

 FROM courseform c WHERE c.application.applicant =: applicant