MybatisMapper 动态映射（增删改查）

//接口内容以及注意事项

package cn.jy.mybatis.mapper;

import java.util.List;

import cn.jy.mybatis.pojo.User;

public interface UserMapper {
    //四个原则
    //1  .xml中的名称空间要绑定此接口      <mapper namespace="cn.jy.mybatis.mapper.UserMapper">
    //2  接口的方法名必须跟   .xml文件的id名一致
    //3  接口中的方法的返回值类型要跟  .xml返回值类型一致
    //4  接口中的方法的参数类型要跟  .xml文件的传入的参数类型一致
    
    User findUserById(int id);
    List<User> findUserByUserName(String username);
    void insertUser(User u);
    void updateUserById(User u);
    void deleteUserById(int u);
}

//.xml 配置文件

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE mapper
 3 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 5 <!-- sql语句 -->
 6 <mapper namespace="cn.jy.mybatis.mapper.UserMapper">
 7    <!-- 通过id 查找用户 -->
 8    <select id="findUserById" parameterType="Integer" resultType="cn.jy.mybatis.pojo.User">
 9        select * from user where id=#{qiang}
10    </select>
11    <!-- 模糊查询 -->
12    <select id="findUserByUserName" parameterType="String" resultType="cn.jy.mybatis.pojo.User">
13        select * from user where username like "%"#{qaingtong}"%"
14    </select>
15    <!--添加用户 -->
16     <insert id="insertUser" parameterType="cn.jy.mybatis.pojo.User" >
17          insert into user (username,birthday,address,sex)values (#{username},#{birthday},#{address},#{sex})
18    </insert>
19    <!-- 更新 -->
20    <update id="updateUserById" parameterType="cn.jy.mybatis.pojo.User">
21         update user
22         set username=#{username},sex=#{sex},birthday=#{birthday},address=#{address}
23         where id=#{id}
24    </update>
25    <!-- 删除 -->
26    <delete id="deleteUserById" parameterType="Integer">
27            delete from user
28            where id=#{DDDD}
29    </delete> 
30 </mapper>

//sqlMapConfig.xml主配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

<!-- 别名 包以其子包下所有类 头字母大小都行-->
<typeAliases>
<!-- <typeAlias type="cn.lijun.mybatis.pojo.User" alias="User"/> -->
<package name="cn.jy.mybatis.pojo"/>
</typeAliases>
<!-- 和spring整合后 environments配置将废除 -->
<environments default="development">
<environment id="development">
<!-- 使用jdbc事务管理 -->
<transactionManager type="JDBC" />
<!-- 数据库连接池 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url"
value="jdbc:mysql://localhost:3306/day58?characterEncoding=utf-8" />
<property name="username" value="root" />
<property name="password" value="root" />
</dataSource>
</environment>
</environments>
<mappers>
       <mapper resource="sqlMap/User.xml"/> <!--  上一篇所用到的-->
       <mapper resource="cn/jy/mybatis/mapper/UserMapper.xml"/>
</mappers>
</configuration>

 //测试类

package cn.jy.mybatis.mapper;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

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 cn.jy.mybatis.pojo.User;

public class MybatisMapperTest {
@Test
public void TestMapper() throws IOException{
    String re="sqlMapConfig.xml";
      InputStream resourceAsStream = Resources.getResourceAsStream(re);
       SqlSessionFactory build = new SqlSessionFactoryBuilder().build(resourceAsStream);
        SqlSession openSession = build.openSession();
      
       //帮助我们给接口创建实现类 
       UserMapper mp=openSession.getMapper(UserMapper.class);
       
      //1 根据id查找
//       User findUserById = mp.findUserById(22);
//      System.out.println(findUserById);
      
      
      //2 根据名字模糊查找
//        List<User> findUserByUserName = mp.findUserByUserName("小明");
//        for(User a:findUserByUserName){
//             System.out.println(a);
//        }
      //3 添加操作 
//        User user = new User();
//        user.setAddress("北京");
//        user.setBirthday(new Date());
//        user.setSex("男");
//        user.setUsername("殷總");
//        mp.insertUser(user);
//        openSession.commit();
     
      //4  更新操作
         User user = new User();
         user.setAddress("北京");
         user.setBirthday(new Date());
         user.setId(31);
         user.setSex("男");
         user.setUsername("王总666");
         mp.updateUserById(user);
         openSession.commit();
       //刪除操作
//       User user = new User();
//       mp.deleteUserById(26);
//       openSession.commit();
}
}

//文件位置关系