java - 自动生成的实体类出现 Netbeans @JoinColoumns 错误

Question

我使用 Netbeans 7.4 从数据源创建实体。

所有具有复合主键的实体都会出现错误。错误如下所示。

我在堆栈溢出上搜索过这个问题，通常是因为人们没有定义连接列。但我已经做到了。我也不确定 netbeans 生成的代码中如何存在错误。

这是我的 MySQL 数据库的图像，我对其进行了正向设计以创建这些实体:

任何帮助将不胜感激!

这里是唯一相关的代码

缺席实体:

public class Absence implements Serializable {
    private static final long serialVersionUID = 1L;
    @EmbeddedId
    protected AbsencePK absencePK;
    @Basic(optional = false)
    @NotNull
    @Column(name = "idAbsence")
    private int idAbsence;
    @Basic(optional = false)
    @NotNull
    @Column(name = "Date")
    @Temporal(TemporalType.DATE)
    private Date date;
    @Size(max = 35)
    @Column(name = "type")
    private String type;
    @Lob
    @Size(max = 65535)
    @Column(name = "remark")
    private String remark;
    @JoinColumn(name = "TimeTable_Period", referencedColumnName = "Period", insertable = false, updatable = false)
    @ManyToOne(optional = false)
    private Timetable timetable;
    @JoinColumn(name = "Student_idStudent", referencedColumnName = "idStudent", insertable = false, updatable = false)
    @ManyToOne(optional = false)
    private Student student;
    @JoinColumn(name = "Class_idClass", referencedColumnName = "idClass", insertable = false, updatable = false)
    @ManyToOne(optional = false)
    private Class class1; 

缺席PK实体:

@Embeddable
public class AbsencePK implements Serializable {
    @Basic(optional = false)
    @NotNull
    @Column(name = "Class_idClass")
    private int classidClass;
    @Basic(optional = false)
    @NotNull
    @Column(name = "Student_idStudent")
    private int studentidStudent;
    @Basic(optional = false)
    @NotNull
    @Column(name = "TimeTable_Period")
    private int timeTablePeriod;

    public AbsencePK() {
    }

    public AbsencePK(int classidClass, int studentidStudent, int timeTablePeriod) {
        this.classidClass = classidClass;
        this.studentidStudent = studentidStudent;
        this.timeTablePeriod = timeTablePeriod;
    }

错误:

原因:异常 [EclipseLink-7220](Eclipse 持久性服务 - 2.5.0.v20130507-3faac2b):org.eclipse.persistence.exceptions.ValidationException异常描述:实体类[class com.fyp.simstest.Absence]中带注释的元素[字段时间表]上的@JoinColumns不完整。当源实体类使用复合主键时，必须使用@JoinColumns为每个连接列指定@JoinColumn。必须在每个这样的@JoinColumn 中指定名称和referencedColumnName 元素。在 org.eclipse.persistence.exceptions.ValidationException.incompleteJoinColumnsSpecified(ValidationException.java:1847)

编辑

时间表

@Entity
@Table(name = "timetable")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Timetable.findAll", query = "SELECT t FROM Timetable t"),
    @NamedQuery(name = "Timetable.findByPeriod", query = "SELECT t FROM Timetable t WHERE t.timetablePK.period = :period"),
    @NamedQuery(name = "Timetable.findByDay", query = "SELECT t FROM Timetable t WHERE t.timetablePK.day = :day"),
    @NamedQuery(name = "Timetable.findByClassidClass", query = "SELECT t FROM Timetable t WHERE t.timetablePK.classidClass = :classidClass")})
public class Timetable implements Serializable {
    private static final long serialVersionUID = 1L;
    @EmbeddedId
    protected TimetablePK timetablePK;
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "timetable")
    private Collection<Absence> absenceCollection;
    @JoinColumn(name = "Class_idClass", referencedColumnName = "idClass", insertable = false, updatable = false)
    @ManyToOne(optional = false)
    private Class class1;

    public Timetable() {
    }

    public Timetable(TimetablePK timetablePK) {
        this.timetablePK = timetablePK;
    }

时间表PK

Embeddable
public class TimetablePK implements Serializable {
    @Basic(optional = false)
    @NotNull
    @Column(name = "Period")
    private int period;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 45)
    @Column(name = "Day")
    private String day;
    @Basic(optional = false)
    @NotNull
    @Column(name = "Class_idClass")
    private int classidClass;

    public TimetablePK() {
    }

    public TimetablePK(int period, String day, int classidClass) {
        this.period = period;
        this.day = day;
        this.classidClass = classidClass;
    }

编辑两个

Answer 1

您的图表表明 TimeTable 表的主键由三列组成(Period、Day 和 Class_idClass)。您需要向 Absence.timeTable 添加一个注释，如下所示:

public class Absence implements Serializable {
    ...
    @JoinColumns[
        @JoinColumn(name = "TimeTable_Period", referencedColumnName = "Period", ...),
        @JoinColumn(name = "????", referencedColumnName = "Day", ...),
        @JoinColumn(name = "Class_idClass", referencedColumnName = "Class_idClass", ...)
    ]
    @ManyToOne(optional = false)
    private TimeTable timeTable;
    ...
}