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