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，我想将它作为主键和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());
    }

}

我可以使用@Embedded和字段上的@Id属性将@Embeddable和其他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

根据您使用复合键时应使用的规范和@EmbeddedId或@IdClass。

如果依赖实体类另外具有主键属性对应于父母主键或父母的主键有一个复合主键，必须使用嵌入式id或id类指定从属实体的主键。它不是父实体和从属实体都使用嵌入式的必要条件 id或者两者都使用id类来表示复合主键父级有一个复合键。

问题是：

我正在使用上面的GROUP_DEPT，DEPTID映射复合主键和EFFDT如下。 hibernate是否支持这个。？

是的，hibernate支持，但你应该使用@EmbeddedId，我知道这需要创建一个新的类来处理密钥，但据我所知，这需要完成。

使用@Embedded和@Id的Hibernate复合主键

1 个答案: