一、mybatis的增删改查
1、修改hotelMapper接口
package com.pjf.mybatis.dao;
import com.pjf.mybatis.po.Hotel;
public interface HotelMapper {
public Hotel getHotel(Integer i);
public void updateHotel(Hotel hotel);
public void insertHotel(Hotel hotel);
public void deleteHotel(Integer i);
}
2、修改hotelMapper.xml文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.pjf.mybatis.dao.HotelMapper">
<!-- public Hotel getHotel(Integer i); -->
<select id="getHotel" resultType="com.pjf.mybatis.po.Hotel">
select id,hotel_name as
hotelName, hotel_address as hotelAddress, price from hotel
where
id=#{id}
</select>
<!-- public void updateHotel(Hotel hotel); -->
<update id="updateHotel" parameterType="com.pjf.mybatis.po.Hotel">
update hotel set
price=#{price} where id =#{id}
</update>
<!-- public void insertHotel(Hotel hotel); -->
<insert id="insertHotel" parameterType="com.pjf.mybatis.po.Hotel">
insert into hotel(id,hotel_name,hotel_address,price)
value(#{id},#{hotelName},#{hotelAddress},#{price})
</insert>
<!-- public void deleteHotel(Integer i); -->
<delete id="deleteHotel">
delete from hotel where id=#{id}
</delete> </mapper>
3、测试类
package com.pjf.mybatis; import java.io.IOException;
import java.io.InputStream; import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test; import com.pjf.mybatis.dao.HotelMapper;
import com.pjf.mybatis.po.Hotel; public class TestHotel { public SqlSessionFactory sqlSessionFactory() throws IOException {
// mybatis的配置文件
String resource = "mybatis_config.xml";
// 使用类加载器加载mybatis的配置文件（它也加载关联的映射文件）TestHotel.class.getClassLoader()
InputStream is = Resources.getResourceAsStream(resource);
// 构建sqlSession的工厂
SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
return sessionFactory;
} // 查
@Test
public void getHotel() throws IOException { SqlSessionFactory sessionFactory = sqlSessionFactory();
SqlSession session = sessionFactory.openSession();
HotelMapper hotelMapper = session.getMapper(HotelMapper.class);
System.out.println(hotelMapper.getClass());
Hotel hotel = hotelMapper.getHotel(1001);
System.out.println(hotel);
session.close();
} // 改
@Test
public void updateHotel() throws IOException {
SqlSessionFactory sessionFactory = sqlSessionFactory();
//注：这里使用sessionFactory.openSession();需要手动提交sql：session.commit();
//如果这里使用sessionFactory.openSession(true);就可以自动提交
SqlSession session = sessionFactory.openSession();
HotelMapper hotelMapper = session.getMapper(HotelMapper.class);
Hotel hotel = new Hotel(1001, "南京玄武饭店", "鼓楼区*路193号", 997);
hotelMapper.updateHotel(hotel);
session.commit();
session.close();
} // 增
@Test
public void insertHotel() throws IOException {
SqlSessionFactory sessionFactory = sqlSessionFactory();
SqlSession session = sessionFactory.openSession();
HotelMapper hotelMapper = session.getMapper(HotelMapper.class);
Hotel hotel = new Hotel(1005, "南京饭店", "鼓楼区*路001号", 997);
hotelMapper.insertHotel(hotel);
session.commit();
session.close();
} // 删
@Test
public void deleteHotel() throws IOException {
SqlSessionFactory sessionFactory = sqlSessionFactory();
SqlSession session = sessionFactory.openSession();
HotelMapper hotelMapper = session.getMapper(HotelMapper.class);
hotelMapper.deleteHotel(1005);
session.commit();
session.close();
}
}
这样就可以实现增删改查了
二、自增主键的获取
修改hotelMapper.xml文件
指定useGeneratedKeys 使用自增主键获得主键值策略，keyProperty 指定对应的主键属性值，也就是mybatis获得主键值后，会传给javaBean中的属性
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.pjf.mybatis.dao.HotelMapper">
<!-- public Hotel getHotel(Integer i); -->
<select id="getHotel" resultType="com.pjf.mybatis.po.Hotel">
select id,hotel_name as
hotelName, hotel_address as hotelAddress, price from hotel
where
id=#{id}
</select>
<!-- public void updateHotel(Hotel hotel); -->
<update id="updateHotel" parameterType="com.pjf.mybatis.po.Hotel">
update hotel set
price=#{price} where id =#{id}
</update>
<!-- public void insertHotel(Hotel hotel); -->
<!-- useGeneratedKeys 使用自增主键获得主键值策略
keyProperty 指定对应的主键属性值，也就是mybatis获得主键值后，会传给javaBean中的属性
-->
<insert id="insertHotel" parameterType="com.pjf.mybatis.po.Hotel" useGeneratedKeys="true" keyProperty="id">
insert into hotel(id,hotel_name,hotel_address,price)
value(#{id},#{hotelName},#{hotelAddress},#{price})
</insert>
<!-- public void deleteHotel(Integer i); -->
<delete id="deleteHotel">
delete from hotel where id=#{id}
</delete> </mapper>
测试
package com.pjf.mybatis; import java.io.IOException;
import java.io.InputStream;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test; import com.pjf.mybatis.dao.HotelMapper;
import com.pjf.mybatis.po.Hotel; public class TestHotel { public SqlSessionFactory sqlSessionFactory() throws IOException {
// mybatis的配置文件
String resource = "mybatis_config.xml";
// 使用类加载器加载mybatis的配置文件（它也加载关联的映射文件）TestHotel.class.getClassLoader()
InputStream is = Resources.getResourceAsStream(resource);
// 构建sqlSession的工厂
SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
return sessionFactory;
}
// 增
@Test
public void insertHotel() throws IOException {
SqlSessionFactory sessionFactory = sqlSessionFactory();
SqlSession session = sessionFactory.openSession();
HotelMapper hotelMapper = session.getMapper(HotelMapper.class);
Hotel hotel = new Hotel(bull, "南京饭店", "鼓楼区*路001号", 997);
hotelMapper.insertHotel(hotel);
//直接打印出自增主键的值
System.out.println(hotel.getId());
session.commit();
session.close();
}
}