使用@Embedded和@Id的Hibernate復合主鍵

Question

我想知道hibernate是否支持使用字段和組件類型的復合主鍵。 所以我有一個@Embeddable組件類型，我想將它作為主鍵與另一列作為復合主鍵使用。

所以我的表“DEPT_HISTORY”有復合主鍵（GROUP_DEPT，DEPTID，EFFDT）。 我將GROUP_DEPT和DEPTID作為@Embeddable組件類型映射到Department類。

@Embeddable public class Department implements Serializable {

    private static final long serialVersionUID = 1L;

    private String departmentGroup;

    private String departmentId;

    public String getDepartmentGroup() {
        return departmentGroup;
    }

    public void setDepartmentGroup(String departmentGroup) {
        this.departmentGroup = departmentGroup;
    }

    public Department withDepartmentGroup(String departmentGroup) {
        setDepartmentGroup(departmentGroup);
        return this;
    }

    public String getDepartmentId() {
        return departmentId;
    }

    public void setDepartmentId(String departmentId) {
        this.departmentId = departmentId;
    }

    public Department withDepartmentId(String departmentId) {
        setDepartmentId(departmentId);
        return this;
    }

    @Override
    public String toString() {
        return Objects.toStringHelper(this).add("departmentGroup", getDepartmentGroup())
                .add("departmentId", getDepartmentId()).toString();
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof Department)) {
            return false;
        }
        Department other = (Department) obj;

        return Objects.equal(getDepartmentGroup(), other.getDepartmentGroup())
                && Objects.equal(getDepartmentId(), other.getDepartmentId());

    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getDepartmentGroup(), getDepartmentId());
    }

}

我正在使用GROUP_DEPT，DEPTID以及EFFDT映射復合主鍵，如下所示。 休眠是否支持這一點。 我有類似的類，但它出於某種原因在這個類上失敗了“引起：org.hibernate.AnnotationException：com.blah.blah.component.Department在用作@EmbeddedId時不能有@Id屬性：com .blah.blah.entity.DepartmentHistory.department

@Entity @Table(name = "dept_history") public class DepartmentHistory implements Serializable {

    private static final long serialVersionUID = 1L;
    private static final String DATETIME_FORMAT = "MM-dd-yyyy HH:mm:ss ZZ";
    protected static final DateTimeFormatter DATE_FORMAT = DateTimeFormat.forPattern(DATETIME_FORMAT);

    @Id
    @Embedded
    @AttributeOverrides({
            @AttributeOverride(name = "departmentGroup", column = @Column(name = "GROUP_DEPT", nullable = false)),
            @AttributeOverride(name = "departmentId", column = @Column(name = "DEPTID", nullable = false)) })
    private Department department;

    @Id
    @Column(name = "EFFDT", nullable = false)
    @Temporal(TemporalType.TIMESTAMP)
    private Calendar effectiveDate;

    @Column(name = "DESCR", nullable = false)
    private String description;

    @Column(name = "MANAGER_ID", nullable = false)
    private String managerId;

    public Department getDepartment() {
        return department;
    }

    public void setDepartment(final Department department) {
        this.department = department;
    }

    public DepartmentHistory withDepartment(final Department department) {
        setDepartment(department);
        return this;
    }

    public Calendar getEffectiveDate() {
        return effectiveDate;
    }

    public void setEffectiveDate(final Calendar effectiveDate) {
        this.effectiveDate = effectiveDate;
    }

    public DepartmentHistory withEffectiveDate(final Calendar effectiveDate) {
        setEffectiveDate(effectiveDate);
        return this;
    }

    public DateTime readEffectiveDateAsDateTime() {
        return calendarToDateTime(effectiveDate);
    }

    public void writeEffectiveDateAsDateTime(final DateTime effectiveDate) {
        this.effectiveDate = dateTimeToCalendar(effectiveDate);
    }

    public DepartmentHistory withEffectiveDateAsDateTime(final DateTime effectiveDate) {
        writeEffectiveDateAsDateTime(effectiveDate);
        return this;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(final String description) {
        this.description = description;
    }

    public DepartmentHistory withDescription(final String description) {
        setDescription(description);
        return this;
    }

    public String getManagerId() {
        return managerId;
    }

    public void setManagerId(final String managerId) {
        this.managerId = managerId;
    }

    public DepartmentHistory withManagerId(final String managerId) {
        setManagerId(managerId);
        return this;
    }

    @Override
    public String toString() {
        return Objects.toStringHelper(this).add("department", getDepartment())
                .add("effectiveDate", DATE_FORMAT.print(readEffectiveDateAsDateTime()))
                .add("description", getDescription()).add("managerId", getManagerId()).toString();
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof DepartmentHistory)) {
            return false;
        }
        DepartmentHistory other = (DepartmentHistory) obj;

        return Objects.equal(getDepartment(), other.getDepartment())
                && Objects.equal(getEffectiveDate(), other.getEffectiveDate());

    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getDepartment(), getEffectiveDate());
    }

}

我是否可以使用@Embedded和字段上的@Id屬性將@Embeddable和另一個字段組合成復合主鍵。 我不想將（GROUP_DEPT，DEPTID，EFFDT）作為@EmbeddedId，因為這樣的組件類型沒有意義，我不想創建一個在我的域中沒有任何意義的類只是用作復合主鍵。 僅包含（GROUP_DEPT，DEPTID）的組件部門作為一個部門是有意義的。 非常感謝。

Answer 1

根據您使用復合鍵時應使用的規范和@EmbeddedId或@IdClass。

如果從屬實體類除了與父主鍵對應的主鍵屬性之外還具有主鍵屬性，或者父節點具有復合主鍵，則必須使用嵌入式id或id類來指定從屬實體的主鍵。 當父組件具有復合鍵時，父實體和從屬實體都不必使用嵌入式ID或兩者都使用id類來表示復合主鍵。

問題是：

我正在使用GROUP_DEPT，DEPTID以及EFFDT映射復合主鍵，如下所示。 休眠是否支持這一點。

是的，hibernate支持，但你應該使用@EmbeddedId，我知道這需要創建一個新類來處理密鑰，但據我所知，這需要完成。