许多到许多Hibernate映射与额外的列？ [英] Many to many hibernate mapping with extra columns?

问题描述

你好，我有多对多的连接表中的额外列映射。
表结构看起来像这样。

 表供应商{vendor_id，vendor_name，vendor_password等} 
 table student {student_id，student_name，student_password等} 
 table test {test_id，test_subject，test_price，test_level等。} 
  

关系如下

  vendor to test  - >多对多
学生来测试 - >多对多
  

link

 表vendor_student_test {vendor_id，student_id，test_id，purchasedDate，assignedDate，writtenDate，result} 
  

我创建了POJO类如下：
$ b

1. Vendor.java
   

 公共类供应商{
 Long vendorId; 
 Set< VendorStudentTest>测试; 
 //设定并获得
} 
  

1. Student.java

 公开课学生{
 Long studentId; 
 Set< VendorStudentTest>测试; 
 //设定并获得
} 
  

1. Test.java

  public class Test {
 Long test_id; 
 double test_price; 
 //设置并获取剩余字段
} 
  

1. VendorStudentTest.java
   

  public class VendorStudentTest {
 public VendorStudentTestPK vendorStudentTestPK; 
日期购买日期; 
日期assignDate; 
日期书写日期; 
双倍结果; 
 //设置并相应得到
} 
  

<

  public class VendorStudentTestPK {
 Long vendor_id; 
 Long student_id; 
 Long test_id; 
 
 code $ <$ $ p 
 

Hibernate映射文件如下

vendor.hbm.xml

 < set name =tests表=vendor_student_test
 inverse =truelazy =truefetch =select> 
< key> 
< column name =vendor_idnot-null =true/> 
< / key> 
<一对多等级=VendorStudentTest/> 
< / set> 
  

vendor_student_test.hbm.xml

 < composite-id name =vendorStudentTestPK
 class =com.onlineexam.model.VendorStudentTestPK> 
 
< key-property name =vendorcolumn =vendor_id
 type =java.lang.Long/> 
  type =java.lang.Long/> 
< key-property name =testcolumn =test_idtype =java.lang.Long/> 
 
< / composite-id> 
  

student.hbm.xml

 < set name =teststable =vendor_student_test
 inverse =truelazy =truefetch =select> 
< key> 
< column name =student_idnot-null =true/> 
< / key> 
<一对多等级=VendorStudentTest/> 
< / set> 
  

test.hbm.xml

  //这是映射到其他表
  

，这是否正确的映射？

解决方案

解决方案与注释案例可以在这里找到

如何从连接表创建多个到多个Hibernate映射的附加属性？使用xml文件的解决方案可以在这里找到：
$ b a href =https://stackoverflow.com/questions/3813941/mapping-same-class-relation>映射相同的类关系

和这里：

映射同类关系 - 延续

Hi i have many to many mapping with extra columns in the join table. table structure look like this.

table vendor{vendor_id, vendor_name, vendor_password, etc...}
table student{student_id, student_name, student_password, etc..}
table test{test_id, test_subject, test_price,test_level, etc..}

Relations as follows

vendor to test --> many-to-many
student to test --> many-to-many

link

table vendor_student_test{vendor_id, student_id, test_id, purchasedDate, assignedDate, writtenDate, result}

i created POJO classes as follows

1. Vendor.java

public class Vendor {
Long vendorId;
Set<VendorStudentTest> tests;
//set and get
}

1. Student.java

public class Student{
Long studentId;
Set<VendorStudentTest> tests;
//set and get
}

1. Test.java

public class Test{
Long test_id;
double test_price;
//set and get and remaining fields
}

1. VendorStudentTest.java

public class VendorStudentTest{
public VendorStudentTestPK vendorStudentTestPK;
Date purchasedDate;
Date assignDate;
Date writtenDate;
double result;
//set and get accordingly
}

1. VendorStudentTestPK.java

public class VendorStudentTestPK{
Long vendor_id;
Long student_id;
Long test_id;
}

Hibernate mapping files as follows

vendor.hbm.xml

<set name="tests" table="vendor_student_test"
                inverse="true" lazy="true" fetch="select">
            <key>
                <column name="vendor_id" not-null="true" />
            </key>
            <one-to-many class="VendorStudentTest" />
        </set>

vendor_student_test.hbm.xml

    <composite-id name="vendorStudentTestPK"
        class="com.onlineexam.model.VendorStudentTestPK">

        <key-property name="vendor" column="vendor_id"
            type="java.lang.Long" />
        <key-property name="student" column="student_id"
            type="java.lang.Long" />
        <key-property name="test" column="test_id" type="java.lang.Long" />

    </composite-id>

student.hbm.xml

<set name="tests" table="vendor_student_test"
                inverse="true" lazy="true" fetch="select">
            <key>
                <column name="student_id" not-null="true" />
            </key>
            <one-to-many class="VendorStudentTest" />
        </set>

test.hbm.xml

//this is mapped to other table 

I am new to hibernate, Is this correct mapping?

解决方案

solution with Annotation Case can be found here

How Do I Create Many to Many Hibernate Mapping for Additional Property from the Join Table?

Solution using xml file can be found here: Mapping same class relation

and here:

Mapping same class relation - continuation

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