使用@Embedded和@Id的Hibernate复合主键

Question

我想知道hibernate是否支持使用字段和组件类型的复合主键.所以我有一个@Embeddable组件类型,我想将它作为主键与另一列作为复合主键使用.

所以我的表"DEPT_HISTORY"有复合主键(GROUP_DEPT,DEPTID,EFFDT).我将GROUP_DEPT和DEPTID作为@Embeddable组件类型映射到Department类.

@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映射复合主键,如下所示.休眠是否支持这一点.我有类似的类,但它出于某种原因在这个类上失败了"引起:org.hibernate.AnnotationException:com.blah.blah.component.Department在用作@EmbeddedId时不能有@Id属性: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属性将@Embeddable和另一个字段组合成复合主键.我不想将(GROUP_DEPT,DEPTID,EFFDT)作为@EmbeddedId,因为这样的组件类型没有意义,我不想创建一个在我的域中没有任何意义的类只是用作复合主键.仅包含(GROUP_DEPT,DEPTID)的组件部门作为一个部门是有意义的.非常感谢.

Answer 1

根据规范，当您使用复合键时，您应该使用 @EmbeddedId 或 @IdClass。

如果从属实体类除了与父级主键对应的属性之外还具有主键属性，或者如果父级具有复合主键，则必须使用嵌入的 id 或 id 类来指定从属实体的主键。当父实体具有复合主键时，父实体和从属实体不必都使用嵌入式 id 或都使用 id 类来表示复合主键。

问题是：

我使用 GROUP_DEPT、上面的 DEPTID 和下面的 EFFDT 映射复合主键，如下所示。休眠支持这个吗？

是的，hibernate 支持这一点，但是您应该使用 @EmbeddedId，我知道这需要创建一个新类来处理密钥，但据我所知，这需要完成。