mapper代理（十一）

<?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">
<!-- namespace命名空间，作用就死对sql进行分类化管理，理解sql隔离 注意：使用mapper代理方法开发，namespace有特殊重要的作用（刚开始学还不能理解） -->
<mapper namespace="ql.mybatis.mapper.UserMapper">
    <!-- 在映射文件中配置很多sql语句-->
    <!-- 需求：通过id查询用户表的记录 -->
    <!-- 通过select 执行数据库的查询
    id:标识映射文件的sql
    将sql语句封装到mappedStatement对象中，所以将id称为statement的id
    parameterType:指定输入参数的类型，这里指定int型
    #{}表示一个占位符
    #{id}:其中的id表示接受输入的参数，参数名称就是id，如果输入的参数是简单类型，#{}中的参数可以任意
    resultType：指定sql输出的结果的所映射的java对象类型，select指定restultType表示将单条记录映射成java对象
    -->
    <select id="findUserById" parameterType="int" resultType="ql.mybatis.pojo.User">
        select * from User where id=#{id}
    </select>
    
    <select id="findUserById2" parameterType="ql.mybatis.pojo.User" resultType="ql.mybatis.pojo.User">
        select * from User where sex=#{sex} and address=#{address} 
    </select>
    
    <!-- 根据用户名称模糊查询用户信息，可能返回多条
    resultType：指定就是单条记录所映射的java对象 类型
    ${}:表示拼接sql串，将接收到参数的内容不加任何修饰拼接在sql中。
    使用${}拼接sql，引起 sql注入
    ${value}：接收输入 参数的内容，如果传入类型是简单类型，${}中只能使用value
     -->
    <select id="findUserByName" parameterType="String" resultType="ql.mybatis.pojo.User">
        SELECT * FROM USER WHERE username LIKE ‘%${value}%‘
    </select>

    <!-- 添加用户 
    parameterType：指定输入 参数类型是pojo（包括 用户信息）
    #{}中指定pojo的属性名，接收到pojo对象的属性值，mybatis通过OGNL获取对象的属性值
    -->
    <insert id="insertUser" parameterType="ql.mybatis.pojo.User">
        insert into user(username,birthday,sex,address) value(#{username},#{birthday},#{sex},#{address})
    </insert>
    
    <!-- 删除用户 -->
    <delete id="deleteUser" parameterType="java.lang.Integer">
     delete from user where id=#{id}
    </delete>
    
    <!-- 更新用户
    必须指定id，否则将会将表的内容全部更新
     -->
    <update id="updateUser" parameterType="ql.mybatis.pojo.User">
    update user set username=#{username},birthday=#{birthday},sex=#{sex},address=#{address} where id=#{id}
    </update>
</mapper>

package ql.mybatis.mapper;

import java.util.List;

import ql.mybatis.pojo.User;

public interface UserMapper {

    public User findUserById(int id) throws Exception;
    public List<User> findUserByName(String name) throws Exception;
    public User findUserById2(User user) throws Exception;
    public void insertUser(User user) throws Exception;
    public void deleteUser(int id) throws Exception;
}

package ql.mybatis.test;

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.Before;
import org.junit.Test;

import ql.mybatis.mapper.UserMapper;
import ql.mybatis.pojo.User;

public class UserMapperTest {

    SqlSession sqlSession = null;

    @Before
    public void setUp() throws Exception {
        // mybatis配置文件
        String resource = "SqlMapConfig.xml";
        // 得到配置文件流
        InputStream inputStream = Resources.getResourceAsStream(resource);
        // 创建会话工厂，传入mybatis的配置文件信息
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder()
                .build(inputStream);
        sqlSession = sqlSessionFactory.openSession();
    }

    @Test
    public void testFindUserById() throws Exception {

        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        User user = userMapper.findUserById(22);
        System.out.println(user);

    }

    @Test
    public void testFindUserByName() throws Exception {
        // 得到代理对象，接口回调
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        List<User> list = userMapper.findUserByName("小明");
        System.out.println(list);
    }

    @Test
    public void testInsertUser() throws Exception {

        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        User user = new User();
        user.setSex("1");
        user.setAddress("北京市");
        user.setBirthday(new Date());
        user.setUsername("王大东");
        userMapper.insertUser(user);
        sqlSession.commit();

    }

    @Test
    public void testDeleteUser() throws Exception {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        userMapper.deleteUser(10);
        sqlSession.commit();
    }
    @Test
    public void testFindUserById2() throws Exception {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        User user=new User();
        user.setSex("1");
        user.setAddress("福建福州");
        User user2=userMapper.findUserById2(user);
        System.out.println(user2);
    }

}

<mapper resource="mapper/UserMapper.xml"/>