如何使用Hibernate中的現有數據處理多對多關系

Question

我有三個表，即，personalinfo，groups_designation，groups_desig_category

• personalinfo：pid（個人ID）
• groups_designation：gid（組ID）
• groups_desig_category：gid，pid

實際上，我在兩個表的個人信息中都有數據（personalinfo，groups_designation）。因此，我們提供了一個屏幕。在該屏幕中，用戶選擇組並分配個人ID，並將數據提取到groups_desig_category表中。在這種情況下，我映射為

Personal.hbm.xml:-

<set name="empwthgrp" inverse="true" lazy="true"  table="groups_desig_category">
 <key>
    <column name="pid" not-null="true" />
  </key>

            <many-to-many entity-name="com.aims.beans.DesignationGroupBean">
                <column name="gid" not-null="true" />
            </many-to-many>

</set>

Personal.java：-

/**
 * 
 */
private static final long serialVersionUID = 1L;
private int pid,deptno;
private String name,designation;
private Address address;
private Address permentaddress;
private Set famildtlslst;
private Set empwthgrp=new HashSet();
public Set getEmpwthgrp() {
    return empwthgrp;
}
public void setEmpwthgrp(Set empwthgrp) {
    this.empwthgrp = empwthgrp;
}
public Set getFamildtlslst() {
    return famildtlslst;
}
public void setFamildtlslst(Set famildtlslst) {
    this.famildtlslst = famildtlslst;
}
public Address getPermentaddress() {

    return permentaddress;
}
public void setPermentaddress(Address permentaddress) {

    this.permentaddress = permentaddress;
}
public Address getAddress() {

    return address;
}
public void setAddress(Address address) {
    this.address = address;
}
public int getDeptno() {
    return deptno;
}
public void setDeptno(int deptno) {
    this.deptno = deptno;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public int getPid() {
    return pid;
}
public void setPid(int pid) {
    this.pid = pid;
}
public String getDesignation() {
    return designation;
}
public void setDesignation(String designation) {
    this.designation = designation;
}

GroupingDesig.hbm.xml：-

<class name="beans.DesignationGroupBean" table="groups_designation" proxy=beans.DesignationGroupBean">

<id name="gid" column="gid" type="java.lang.Integer">
 <generator class="sequence"><param name="sequence">gid_seq</param> </generator>
</id>
<property name="gname"  type="java.lang.String" column="gname" not-null="true" />
<property name="description"  type="java.lang.String" column="description" not-null="true" />
<set name="grpwthemp" inverse="true" lazy="true" table="groups_desig_category">
 <key>
    <column name="gid" not-null="true" />
  </key>
             <many-to-many entity-name="com.aims.beans.Personal">
                <column name="pid" not-null="true" />
            </many-to-many>
</set>
</class>

DesignationGroupBean.java:-

private int gid;
private String gname,description;
private Set grpwthemp=new HashSet();
public Set getGrpwthemp() {
    return grpwthemp;
}
public void setGrpwthemp(Set grpwthemp) {
    this.grpwthemp = grpwthemp;
}
public String getDescription() {
    return description;
}
public void setDescription(String description) {
    this.description = description;
}
public int getGid() {
    return gid;
}
public void setGid(int gid) {
    this.gid = gid;
}
public String getGname() {
    return gname;
}
public void setGname(String gname) {
    this.gname = gname;
}

實際上我正在嘗試session.saveOrUpdate（pBean）。但是它不起作用。可能會改變一對多和多對一的關系，而不是多對多的關系。我認為這不適合這種情況。在這種情況下該如何處理？如果使用逆向工程，那么它將創建為一對多和多對一關系？ 為什么？請幫助我。

更新：-

我是在一對多和多對一的休眠狀態下實現的，而在數據庫中它是多對多的關系。那么它的工作原理如下：

GroupingDesig.hbm.xml：-

<set name="grpwthemp" inverse="true" lazy="true" table="groups_desig_category">
 <key>
    <column name="gid" not-null="true" />
  </key>
                <one-to-many class="com.aims.beans.GroupAssignment"/>


           <!--  <many-to-many entity-name="com.aims.beans.Personal">
                <column name="pid" not-null="true" />
            </many-to-many>-->

</set>

Personal.hbm.xml

<set name="empwthgrp" inverse="true" lazy="true"  table="groups_desig_category">
 <key>
    <column name="pid" not-null="true" />
  </key>
    <one-to-many class="com.aims.beans.GroupAssignment"/>

            <!--
            <many-to-many entity-name="com.aims.beans.DesignationGroupBean">
                <column name="gid" not-null="true" />
            </many-to-many>-->

</set>

AssigGroupingDesig.hbm.xml：-

<many-to-one name="personal" column="pid" class="com.aims.beans.Personal" not-null="true"></many-to-one>
<many-to-one name="desigdt" column="gid" class="com.aims.beans.DesignationGroupBean" not-null="true"></many-to-one>

什么時候來圖片關系船？。我在Web上搜索了多對多實例。

湄公河多對多

請幫我。 我的問題是何時實時出現/使用多對多關系船？

更新2：-

謝謝。刪除反向標簽的工作正常。但我懷疑刪除查詢的生成。請檢查日志

 /* load com.beans.Personal */ select personal0_.pid as pid0_, personal0_.name as name5_0_, personal0_.DEPTNO as DEPTNO5_0_, personal0_.designation as designat4_5_0_, personal0_.pddress1 as pddress5_5_0_, personal0_.pddress2 as pddress6_5_0_, personal0_.pcity as pcity5_0_, personal0_.pstate as pstate5_0_, personal0_1_.HomeAddress1 as HomeAddr2_7_0_, personal0_1_.HomeAddress2 as HomeAddr3_7_0_, personal0_1_.homecity as homecity7_0_, personal0_1_.homestate as homestate7_0_ from personalinfo personal0_, address personal0_1_ where personal0_.pid=personal0_1_.pid and personal0_.pid=?



delete collection com.beans.Personal.empwthgrp */ delete from groups_desig_category where pid=?




insert collection row com.beans.Personal.empwthgrp */ insert into groups_desig_category (pid, gid) values (?, ?)

為什么生成“從groups_desig_category的pid =？中刪除？”。請幫助我

更新3：-

是的，我使用session.get加載數據，因為我遇到了一些必填字段的異常。這就是我加載數據然后更新記錄的原因

          per=(Personal)session.get(Personal.class,new Integer(pBean.getPid()));
    per.setEmpwthgrp(pBean.getEmpwthgrp());
    session.saveOrUpdate(per);

Answer 1

在多對多映射中，將它們都設置為inverse 。 您需要選擇一個擁有該關系的實體-為此，在映射中，您將刪除inverse="true"設置。 該實體將在保存或更新后將持久化人員與組的關系。

因為在你的問題你貼saveOrUpdate(pBean)我認為pBean是Personal的實體，那么你需要刪除inverse="true"在制定Personal.hbm.xml 。

參考文檔中的更多信息： http : //docs.jboss.org/hibernate/core/3.6/reference/zh-CN/html/associations.html#assoc-bidirectional-join-m2m