2007-12-13

Hibernate Criteria的嵌套查询

假设有Artist和Track实体，是1对多的关系，现在我们想使用Criteria查询所有artist中，其对应的Track实体集合中，有名为track1的Track实体所对应的Artist

比较乱，用SQL来举例

只有artist1和artist2对应的track集合中1有名为“track1”的记录，我们就要找出artist1和artist2来

create table artist(id varchar(20),name varchar(20));
create table track (id varchar(20),name varchar(20),artist_id varchar(20));

insert into artist values("1","artist1");
insert into artist values("2","artist2");
insert into artist values("3","artist3");


insert into track values("1","track1","1");
insert into track values("2","track2","1");
insert into track values("3","track3","1");

insert into track values("4","track1","2");

insert into track values("5","track4","3");
insert into track values("6","track5","3");

 

 pojo:

 

package RelationCriteria;

import java.util.Set;

public class Artist {
   private String id;
   private String name;
   private Set tracks;
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public Set getTracks() {
    return tracks;
}
public void setTracks(Set tracks) {
    this.tracks = tracks;
}
}



package RelationCriteria;

public class Track {
   private String id;
   private String name;
   private Artist artist;
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public Artist getArtist() {
    return artist;
}
public void setArtist(Artist artist) {
    this.artist = artist;
}
}

 

Artist.hbm.xml

 

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping package="RelationCriteria" >
    <class name="RelationCriteria.Artist" table="artist" lazy="true">
       <id name="id" column="id">
         <generator class="uuid.hex"></generator>
       </id>
       <property name="name" column="name"></property>
       <set name="tracks" lazy="true" inverse="true" outer-join="false">
         <key column="artist_id"></key>
         <one-to-many class="RelationCriteria.Track"/>
       </set>
      </class>
</hibernate-mapping>

 

Track.hbm.xml

 

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse - Hibernate Tools
-->
<hibernate-mapping package="RelationCriteria" >
   
    <class name="RelationCriteria.Track" table="track" lazy="true">
       <id name="id" column="id" unsaved-value="null">
         <generator class="uuid.hex"></generator>
       </id>

       <property name="name" column="name"></property>
       <many-to-one name="artist" 
                    column="artist_id"
                    outer-join="true" 
                    class="RelationCriteria.Artist"></many-to-one>
      </class>
</hibernate-mapping>

 

Hibernate.cfg.xml

 

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>

<session-factory>
    <property name="connection.username">root</property>
    <property name="connection.url">
        jdbc:mysql://localhost:3306/schoolproject?characterEncoding=gb2312&amp;useUnicode=true
    </property>
    <property name="dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="myeclipse.connection.profile">mysql</property>
    <property name="connection.password">1234</property>
    <property name="connection.driver_class">
        com.mysql.jdbc.Driver
    </property>
    <property name="hibernate.dialect">
        org.hibernate.dialect.MySQLDialect
    </property>
    <property name="hibernate.show_sql">true</property>
    <property name="current_session_context_class">thread</property>
    <mapping resource="RelationCriteria/Artist.hbm.xml" />
    <mapping resource="RelationCriteria/Track.hbm.xml" />

</session-factory>

</hibernate-configuration>

 

测试代码：

 

package RelationCriteria;

import java.io.File;
import java.util.Iterator;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Expression;

;

public class Test {


    public static void
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