hibernate 多表查询的问题

userBasicInfo中的ID应该是userRegInfo中的外键吧，在userRegInfo里有没有封装一个
UserBasicInfo类型的变量？

<hibernate-mapping default-access="field">
  <class name="org.jbpm.identity.User"
         table="T_SYSTEM_USER">
    <id name="ID" column="ID"><generator class="assigned" /></id>
    <property name="REGNAME" column="REGNAME"/>
    <property name="PASSWORD" column="PASSWORD"/>
    <set name="memberships" cascade="all">
      <key column="USER_" />
      <one-to-many class="org.jbpm.identity.Membership" />
    </set>
    <set name="permissions" cascade="all" table="ID_PERMISSIONS">
      <key column="ENTITY_" foreign-key="none" />
      <element type="org.jbpm.identity.hibernate.PermissionUserType">
        <column name="CLASS_"/>
        <column name="NAME_"/>
        <column name="ACTION_"/>
      </element>
    </set>
  </class>
</hibernate-mapping>
类似这样应该可以

langliu(魑魅魍魉)这是设置一对多关系的吧
设置好了后呢
怎么用Criteria实现查询

不用配置它们的关系，你想想SQL里面要关联两个表，只要字段满足条件就行了

我的SQL语句是这样的
select userRegInfo.regName,userBasicInfo.nickname,userBasicInfo.realName
from userRegInfo inner join userBasicInfo
on userRegInfo.ID = userBasicInfo.ID
where userRegInfo.ID = 1按道理来说,查询出来结果集会有三个字段
可是我打印出来的时候却不行
提示说数组越界的错误

我现在可以解决2个表之间的查询,但是3个以上的表就不知道怎么办了?
我是使用CUSTOMERS表和ORDERS表,是一对多的关系,HBM.XML是如下配置的.
Order.hbm.xml:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping >
   <class name="src.mypack.Order" table="ORDERS">
      <id name="id" type="long" column="ID">
        <generator class="increment"/>
      </id>
      <property name="orderNumber" type="string" >
        <column name="ORDER_NUMBER" length="15" />
      </property>
      <many-to-one name="customer" column="CUSTOMER_ID"  class="src.mypack.Customer"  outer-join="true"  />
    </class>
</hibernate-mapping><?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping >Customer.hbm.xml:
  <class name="src.mypack.Customer" table="CUSTOMERS" >
    <id name="id" type="long" column="ID">
      <generator class="increment"/>
    </id>
    <property name="name" type="string" >
        <column name="NAME" length="15" />
    </property>
    <set name="orders" inverse="true" lazy="true" batch-size="4">
        <key column="CUSTOMER_ID" />
        <one-to-many class="src.mypack.Order" />
     </set>
  </class>
</hibernate-mapping>
然后很简单, 一个Customer.java和一个Order.java.
然后通过DAO去取得,Order的对象, 而Order里面由于有Customer的对象,直接通过Order就可以取得CUSTOMERS表里面的值.
在贴一下,Order.java的SOURCE
package src.mypack;
import java.io.Serializable;
import org.apache.commons.lang.builder.ToStringBuilder;
/** @author Hibernate CodeGenerator */
public class Order implements Serializable {    /** identifier field */
    private Long id;
    /** nullable persistent field */
    private String orderNumber;
    /** nullable persistent field */
    private src.mypack.Customer customer;
    /** full constructor */
    public Order(String orderNumber, src.mypack.Customer customer) {
        this.orderNumber = orderNumber;
        this.customer = customer;
    }
    /** default constructor */
    public Order() {
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getOrderNumber() {
        return this.orderNumber;
    }
    public void setOrderNumber(String orderNumber) {
        this.orderNumber = orderNumber;
    }
    public src.mypack.Customer getCustomer() {
        return this.customer;
    }
    public void setCustomer(src.mypack.Customer customer) {
        this.customer = customer;
    }
    public String toString() {
        return new ToStringBuilder(this)
            .append("id", getId())
            .toString();
    }
}但是要是加上一个表ORDERDETIAL就是ORDERS表的详细内容的表, 是多对一的关系, 我试着从OrderDetail对象去取Order和Customer都是可以的,但从Order开始去取OrderDetail和Customer就不行, 就算是取到了数据变成Order和OrderDetail的一对一.有什么解决办法

再补充一下,增加一个DETAIL表之后,HBM.XML有些改动.
贴出来, 大家指教一下Order.hbm.xml<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping >   <class name="src.mypack.Order" table="ORDERS">
      <id name="id" type="long" column="ID">
        <generator class="increment"/>
      </id>
      <property name="orderNumber" type="string" >
        <column name="ORDER_NUMBER" length="15" />
      </property>
      <many-to-one  name="customer"  column="CUSTOMER_ID"  class="src.mypack.Customer"  outer-join="true" />
    <set  name="orderdetails" inverse="true" lazy="true" batch-size="4">
      <key column="ID" />
      <one-to-many class="src.mypack.Orderdetail"/>
    </set>
    </class>
</hibernate-mapping>新增加的ORDERDETAIL表的HBM.XML
Orderdetail.hbm.xml<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping >  <class name="src.mypack.Orderdetail" table="ORDERDETAIL" >
    <id name="id" type="long" column="ID">
      <generator class="increment"/>
    </id>
    <property name="sum" type="long" >
        <column name="SUM"  length="9"/>
    </property>
    <many-to-one name="order" column="ORDER_ID" class="src.mypack.Order" outer-join="true" />
  </class>
</hibernate-mapping>

Order.java也增加了对OrderDetail的操作
增加一个属性
    /** persistent field */
    private Set orderdetails;
    public Set getOrderdetails() {
        return this.orderdetails;
    }
同时也增加对这个属性的GET和SET
    public void setOrderdetails(Set orderdetails) {
        this.orderdetails = orderdetails;
    }然后想用Order对象去取orderdetails, 是能取到,但是每个orderdetails里面就一条数据,好象是变成了Order和OrderDetail的一对一的关系了.不知道错在哪里

调试易

hibernate 多表查询的问题

解决方案 »