hibernate demo配置和使用 -----类与表映射关系

hibernate.cfg.xml

<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <!-- 通常，一个session-factory节点代表一个数据库 -->
    <session-factory>
    
        <!-- 1. 数据库连接配置 -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql:///hib_demo</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root</property>
        <!-- 
            数据库方法配置， hibernate在运行的时候，会根据不同的方言生成符合当前数据库语法的sql
         -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
        
        
        <!-- 2. 其他相关配置 -->
        <!-- 2.1 显示hibernate在运行时候执行的sql语句 -->
        <property name="hibernate.show_sql">true</property>
        <!-- 2.2 格式化sql -->
        <property name="hibernate.format_sql">true</property>
        <!-- 2.3 自动建表  -->
        <property name="hibernate.hbm2ddl.auto">create</property>
        
        
     
        
    </session-factory>
</hibernate-configuration>

 

 

 

 

组件映射：

car.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
    
    
<hibernate-mapping  package="cn.itcast.compomer" >  
    <class name="car"  table="t_car">
    <id name="id" >
    <generator class="native"/>
    
    </id>
    <property name="name" ></property>
    
     <component name="wheel">
     <property name="size"></property>
     <property name="count"></property>
    
     </component>

    </class>
    </hibernate-mapping>

 

 

car.java

package cn.itcast.compomer;

public class car {
private int id;
private String name;
private wheel wheel;
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public wheel getWheel() {
    return wheel;
}
public void setWheel(wheel wheel) {
    this.wheel = wheel;
}

}

 

wheel.java

package cn.itcast.compomer;

public class wheel {
private int count;
private int size;
public int getCount() {
    return count;
}
public void setCount(int count) {
    this.count = count;
}
public int getSize() {
    return size;
}
public void setSize(int size) {
    this.size = size;
}

}

 

 

app.java

public class app {
    private static SessionFactory  sf;
    static {
        sf=new Configuration().configure().addClass(car.class).buildSessionFactory();

//该处一定要加上   addclass(car.class)     会自动去查找car.hbm.xml


    }
    @Test
    public void testsave() throws Exception{
        Session  session=sf.openSession();
        session.beginTransaction();
        wheel wheel = new wheel();
        wheel.setSize(38);
        wheel.setCount(4);
        
        car car= new car();
        car.setName("bmw");
        car.setWheel(wheel);
        
        session.save(car);
        
        session.getTransaction().commit();
        session.close();

    }


    }

 

 

 

 

二，继承映射

animal.java

public abstract class animal {
private int id;
private String name;
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}

}

 

cat.java

public class cat  extends animal{
private String catchmouse;

public String getCatchmouse() {
    return catchmouse;
}

public void setCatchmouse(String catchmouse) {
    this.catchmouse = catchmouse;
}


}

 

cat.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    
    
    
    <hibernate-mapping  package="cn.itcast.extend1" >  
    <class name="cat"  table="t_cat">
    <id name="id">
    <generator class="native"></generator>
    </id>
    <property name="name"></property>
      <property name="catchmouse"></property>

    </class>
    </hibernate-mapping>

 

hibernate.cfg.xml

<hibernate-configuration>
    <!-- 通常，一个session-factory节点代表一个数据库 -->
    <session-factory>
    
        <!-- 1. 数据库连接配置 -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql:///hib_demo</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root</property>
        <!-- 
            数据库方法配置， hibernate在运行的时候，会根据不同的方言生成符合当前数据库语法的sql
         -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
        
        
        <!-- 2. 其他相关配置 -->
        <!-- 2.1 显示hibernate在运行时候执行的sql语句 -->
        <property name="hibernate.show_sql">true</property>
        <!-- 2.2 格式化sql 
        <property name="hibernate.format_sql">true</property>
        -->
        <!-- 2.3 自动建表  -->
        <property name="hibernate.hbm2ddl.auto">update</property>
        
        
        <!-- 3. 加载所有映射
        <mapping resource="cn/itcast/acollection/user.hbm.xml"/>
         -->
        
    </session-factory>
</hibernate-configuration>

 

app.java

public class app {
    private static SessionFactory  sf;
    static{
        sf= new Configuration().configure().addClass(cat.class).buildSessionFactory();
        
    }

    @Test
    public void getsave(){
        Session  session=sf.openSession();
        session.beginTransaction();
        
/*  cat  cat= new cat();
  cat.setName("dahuamao");
  cat.setCatchmouse("zhuoxiaolaoshu ");
  session.save(cat);*/                 //hibernate.cfg.xml    <property name="hibernate.hbm2ddl.auto">create</property>  创建表内数据时使用该配置

        



 Query q= session.createQuery("from cat"); 

List<cat> list=q.list(); 
System.out.println(list);

//hibernate.cfg.xml    <property name="hibernate.hbm2ddl.auto">update</property>   查询表内数据时使用该配置

 
session.getTransaction().commit(); 
session.close(); 

} 
}

 

 

 

 

animal.class+ cat.class + monkey.class

public class monkey extends animal{
private String eatbanana;

public String getEatbanana() {
    return eatbanana;
}

public void setEatbanana(String eatbanana) {
    this.eatbanana = eatbanana;
}

}

 

 

 

 

三个类对应 一张数据表

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

    <hibernate-mapping  package="cn.itcast.extend2.copy" >  
    <class name="animal"  table="t_animal">
    <id name="id">
    <generator class="native"></generator>
    </id>
    
    < 三个类对应到一张表    需要使用到 筛选器   >
    <discriminator column="type_"></discriminator>
    <property name="name"></property>
    
    
      <subclass  name="cat"  discriminator-value="cat_">
      <property name="catchmouse"></property>
      </subclass>

      <subclass   name="monkey" discriminator-value="monkey_">
      <property name="eatbanana"></property>
      </subclass>
    </class>
    </hibernate-mapping>

        cat cat= new cat();
        cat.setName("大茂华");
        cat.setCatchmouse("捉小老鼠");
        
        monkey m= new monkey();
        m.setName("猴子");
        m.setEatbanana("吃了10个香蕉");
        
        session.save(cat);
        session.save(m);

 

 

 

三个类对应三个表           animal表 :   1  cat     2  monkey  ;      cat 表 ;    monkey 表  

<hibernate-mapping  package="cn.itcast.extend2.copy" >  
    <class name="animal"  table="t_animal">
    <id name="id">
    <generator class="native"></generator>
    </id>

    <property name="name"></property>
    
    <joined-subclass name="cat" table="t_cat">
    <key column ="t_animal_id"></key>
    <property name="catchmouse"></property>
    </joined-subclass>
    
     <joined-subclass  name="monkey"  table="t_monkey">
     <key column="t_animal_id"></key>
     <property name="eatbanana"></property>
     
     </joined-subclass>
    </class>
    </hibernate-mapping>

 

 

 

每个子类映射一张表，父类不对应表（2张表）

<hibernate-mapping  package="cn.itcast.extend2.copy" >  
    <class name="animal"  table="t_animal">
    <id name="id">
    <!-- 如果用union-subclass节点 主键生成策略不能为自增长  不能使用native -->
    <generator class="uuid"></generator>
    </id>

    <property name="name"></property>
    <union-subclass name="cat"  table="t_cat">
    <property name="catchmouse"></property>
    
    </union-subclass>
    
     <union-subclass name="monkey"  table="t_monkey">
    <property name="eatbanana"></property>
    
    </union-subclass>
    </class>
    </hibernate-mapping>

 

public abstract class animal {
private String id;     //   使用uuid后   int  id  需要更改为  String id ;
private String name;
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;
}

}