接上篇《hibernate 映射 bag/idbag值對象 簡單映射》 如果允許給一個User添加多個Task,並且要記錄順序怎麼辦?
這個和List的語義相同用List映射
package com.ccay.test.valueCollection.list.xml;
import java.util.ArrayList;
import java.util.List;
public class User {
private long userId;
private String firstname;
private String lastname;
private List<String> tasks = new ArrayList<String>();
public long getUserId() {
return userId;
}
public void setUserId(long userId) {
this.userId = userId;
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
public List<String> getTasks() {
return tasks;
}
public void setTasks(List<String> tasks) {
this.tasks = tasks;
}
}
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">
<hibernate-mapping>
<class name="com.ccay.test.valueCollection.list.xml.User" table="VAL_COLLECTION_SIMPLE_SET_USER" >
<id name="userId" type="long">
<column name="USER_ID"/>
<generator class="native" />
</id>
<property name="firstname" type="string">
<column name="FIRSTNAME" length="40" />
</property>
<property name="lastname" type="string">
<column name="LASTNAME" length="50" />
</property>
<list name="tasks" table="VAL_COLLECTION_SIMPLE_SET_TASKS">
<key column="USER_ID"/>
<list-index column="POSITION"/>
<element type="string" column="TASK" not-null="true"></element>
</list>
</class>
</hibernate-mapping>
測試
package com.ccay.test.valueCollection.list.xml;
import java.util.ArrayList;
import org.hibernate.Session;
import org.hibernate.Transaction;
import com.ccay.test.HibernateSessionFactory;
public class Test {
@org.junit.Test
public void testDDL(){
Session session = HibernateSessionFactory.getSession();
Transaction transaction = session.beginTransaction();
ArrayList<String> tasks = new ArrayList<String>();
tasks.add("student");
tasks.add("student");
tasks.add("progarm");
tasks.add("doctor");
User user= new User();
user.setFirstname("firstName");
user.setLastname("lastName");
user.setTasks(tasks);
session.save(user);
transaction.commit();
HibernateSessionFactory.closeSession();
}
}
數據腳本
create table VAL_COLLECTION_SIMPLE_SET_TASKS (
USER_ID bigint not null,
TASK varchar(255) not null,
POSITION integer not null,
primary key (USER_ID, POSITION)
)
create table VAL_COLLECTION_SIMPLE_SET_USER (
USER_ID bigint not null auto_increment,
FIRSTNAME varchar(40),
LASTNAME varchar(50),
primary key (USER_ID)
)
alter table VAL_COLLECTION_SIMPLE_SET_TASKS
add index FK839C9A2766CC214F (USER_ID),
add constraint FK839C9A2766CC214F
foreign key (USER_ID)
references VAL_COLLECTION_SIMPLE_SET_USER (USER_ID)
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