1.总
- set:不允许重复、无序
- list:有序、重复
- map:key-value对形式
2.map与set标签中的element子标签映射的是原子类型（string、data、int、long...），即就是能够直接映射到数据库表字段上的类型，而one-to-many映射的则是实体类型，指的是无法映射到表的某个字段，而是要映射到整张表的类型。
3.map
（1）原子类型
public class Team
{
private String id;
private String name;
private Map students = new HashMap();
}
<hibernate-mapping>
<class name="com.liule.hibernate.Team" table="team">
<id name="id" column="id" type="string">
<generator class="uuid"></generator>
</id>
<property name="name" type="string">
<column name="name" length="50"></column>
</property>
<map name="students" table="team_student"> <!-- table：存放map内的key-value对的值 -->
<key column="team_id"></key> <!-- 在team_student表内靠team_id联系到team表 -->
<index column="name" type="string"></index> <!-- 在map内key的值 -->
<element column="description" type="string" ></element> <!-- map内value的值 -->
</map>
</class>
</hibernate-mapping>
public static void main(String[] args)
{
//生成表
SchemaExport export = new SchemaExport(new Configuration().configure());
export.create(true,true);
}
Team team = new Team();
team.setName("team");
Map map = team.getStudents();
map.put("zhangsan","sdas");
map.put("lisi","sadasd");
Session session = sf.openSession();
Transaction ts = null;
try
{
ts = session.beginTransaction();
session.save(team);
ts.commit();
}
catch(Exception ex)
{
if(null != ts)
{
ts.rollback();
}
}
finally
{
session.close();
}
（2）实体类型
public class Team
{
private String id;
private String name;
private Map students = new HashMap();
}
public class Student
{
private String id;
private String name;
private String cardId;
private int age;
private Team team;
}
<hibernate-mapping>
<class name="com.liule.hibernate.Team" table="team">
<id name="id" column="id" type="string">
<generator class="uuid"></generator>
</id>
<property name="name" type="string">
<column name="name" length="50"></column>
</property>
<map name="students" table="team_student" cascade="all"> <!-- table：存放map内的key-value对的值 -->
<key column="team_id"></key> <!-- 在team_student表内靠team_id联系到team表 -->
<index column="card_id" type="string"></index> <!-- 在map内key的值 -->
<one-to-many class="com.liule.hibernate.Student"/><!-- map内value的值 -->
</map>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="com.liule.hibernate.Student" table="Student">
<id name="id" column="id" type="string">
<generator class="uuid"></generator>
</id>
<property name="name" type="string">
<column name="name" length="50"></column>
</property>
<property name="cardId" column="card_id" type="string"></property><!-- key -->
<property name="age" column="age" type="int"></property>
<many-to-one name="team" column="team_id" class="com.liule.hibernate.Team"></many-to-one>
</class>
</hibernate-mapping>
public static void main(String[] args)
{
Team team = new Team();
team.setName("team1");
Student student = new Student();
student.setAge(12);
student.setName("liule");
student.setTeam(team);
team.getStudents().put("123456",student);
Session session = sf.openSession();
Transaction ts = null;
try
{
session.save(team);
ts = session.beginTransaction();
ts.commit();
}
catch(Exception ex)
{
ex.printStackTrace();
if(null != ts)
{
ts.rollback();
}
}
finally
{
session.close();
}
}
4.set
public class Team
{
private String id;
private String name;
private Set students = new HashSet();
}
<hibernate-mapping>
<class name="com.liule.hibernate.Team" table="team">
<id name="id" column="id" type="string">
<generator class="uuid"></generator>
</id>
<property name="name" type="string">
<column name="name" length="50"></column>
</property>
<set name="students" table="student" cascade="all"> <!-- 将set内容，设置在team_table表 -->
<key column="team_id"></key>
<element column="name" type="string"></element><!-- column映射到name这一列 -->
</set>
</class>
</hibernate-mapping>
public static void main(String[] args)
{
Team team = new Team();
team.setName("team1");
team.getStudents().add("zhangsan");
Session session = sf.openSession();
Transaction ts = null;
try
{
session.save(team);
ts = session.beginTransaction();
ts.commit();
}
catch(Exception ex)
{
ex.printStackTrace();
if(null != ts)
{
ts.rollback();
}
}
finally
{
session.close();
}
}
5.list
public class Team
{
private String id;
private String name;
private List students = new ArrayList();
}
public class Student
{
private String id;
private String name;
private String cardId;
private int age;
private Team team;
<hibernate-mapping>
<class name="com.liule.hibernate.Team" table="team">
<id name="id" column="id" type="string">
<generator class="uuid"></generator>
</id>
<property name="name" type="string">
<column name="name" length="50"></column>
</property>
<list name="students" table="student" cascade="all">
<key column="team_id"></key>
<index column="index_"></index><!-- 所存放的是索引的位置 -->
<one-to-many class="com.liule.hibernate.Student"/>
</list>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="com.liule.hibernate.Student" table="Student">
<id name="id" column="id" type="string">
<generator class="uuid"></generator>
</id>
<property name="name" type="string">
<column name="name" length="50"></column>
</property>
<property name="cardId" column="card_id" type="string"></property><!-- key -->
<property name="age" column="age" type="int"></property>
<many-to-one name="team" column="team_id" class="com.liule.hibernate.Team"></many-to-one>
</class>
</hibernate-mapping>
public static void main(String[] args)
{
Team team = new Team();
team.setName("team1");
Student student1 = new Student();
Student student2 = new Student();
Student student3 = new Student();
student1.setAge(10);
student1.setCardId("asd");
student1.setName("zhangsan");
student1.setTeam(team);
student2.setAge(11);
student2.setCardId("asdsa");
student2.setName("lisi");
student2.setTeam(team);
student3.setAge(12);
student3.setCardId("asasad");
student3.setName("wangwu");
student3.setTeam(team);
team.getStudents().add(student1);
team.getStudents().add(student2);
team.getStudents().add(student3);
Session session = sf.openSession();
session.save(team);
Transaction ts = null;
try
{
session.save(team);
ts = session.beginTransaction();
ts.commit();
}
catch(Exception ex)
{
ex.printStackTrace();
if(null != ts)
{
ts.rollback();
}
}
finally
{
session.close();
}
}
时间： 2024-08-05 19:35:03