Mybatis急速入门（上篇）

5.2创建UserMapper.xml

<?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:根标签;namespace;命名空间;随便写;一般保证命名空间唯一 ;为了使用接口动态代理;这里必须是接口的全路径名-->
<mapper namespace=;com.luoke.mapper.UserMapper;>
    <!--
       1.#{},预编译的方式preparedstatement;使用占位符替换;防止sql注入;一个参数的时候;任意参数名可以接收
       2.${},普通的Statement;字符串直接拼接;不可以防止sql注入;一个参数的时候;必须使用${value}接收参数
     -->
    <select id=;queryUserByTableName; resultType=;com.luoke.entity.User;>
        select * from ${tableName}
    </select>

    <select id=;login; resultType=;com.luoke.entity.User;>
        select * from tb_user where user_name = #{userName} and password = #{password}
    </select>

    <!-- statement;内容;sql语句。
       id;唯一标识;随便写;在同一个命名空间下保持唯一;使用动态代理之后要求和方法名保持一致
       resultType;sql语句查询结果集的封装类型;使用动态代理之后和方法的返回类型一致;resultMap;二选一
       parameterType;参数的类型;使用动态代理之后和方法的参数类型一致
     -->
    <select id=;queryUserById; resultType=;com.luoke.entity.User;>
        select * from tb_user where id = #{id}
    </select>
    <select id=;queryUserAll; resultType=;com.luoke.entity.User;>
        select * from tb_user
    </select>
    <!-- 新增的Statement
       id;唯一标识;随便写;在同一个命名空间下保持唯一;使用动态代理之后要求和方法名保持一致
       parameterType;参数的类型;使用动态代理之后和方法的参数类型一致
       useGeneratedKeys:开启主键回写
       keyColumn;指定数据库的主键
       keyProperty;主键对应的pojo属性名
     -->
    <insert id=;insertUser; useGeneratedKeys=;true; keyColumn=;id; keyProperty=;id;
            parameterType=;com.luoke.entity.User;>
        INSERT INTO tb_user (
            id,
            user_name,
            password,
            name,
            age,
            sex,
            birthday,
            created,
            updated
        )
        VALUES
        (
            null,
            #{userName},
            #{password},
            #{name},
            #{age},
            #{sex},
            #{birthday},
            NOW(),
            NOW()
        );
    </insert>
    <!--
       更新的statement
       id;唯一标识;随便写;在同一个命名空间下保持唯一;使用动态代理之后要求和方法名保持一致
       parameterType;参数的类型;使用动态代理之后和方法的参数类型一致
     -->
    <update id=;updateUser; parameterType=;com.luoke.entity.User;>
        UPDATE tb_user
        <trim prefix=;set; suffixOverrides=;,;>
            <if test=;userName!=null;>user_name = #{userName},</if>
            <if test=;password!=null;>password = #{password},</if>
            <if test=;name!=null;>name = #{name},</if>
            <if test=;age!=null;>age = #{age},</if>
            <if test=;sex!=null;>sex = #{sex},</if>
            <if test=;birthday!=null;>birthday = #{birthday},</if>
            updated = now(),
        </trim>
        WHERE
        (id = #{id});
    </update>
    <!--
       删除的statement
       id;唯一标识;随便写;在同一个命名空间下保持唯一;使用动态代理之后要求和方法名保持一致
       parameterType;参数的类型;使用动态代理之后和方法的参数类型一致
     -->
    <delete id=;deleteUserById; parameterType=;java.lang.String;>
        delete from tb_user where id=#{id}
    </delete>
</mapper>

    <mappers>
        <mapper resource=;mapper/MyMapper.xml;></mapper>
        <mapper resource=;mapper/UserDaoMapper.xml;></mapper>
        <mapper resource=;mapper/UserMapper.xml;></mapper>
    </mappers>

public class UserMapperTest {
    public UserMapper userMapper;

    ;Before
    public void setUp() throws IOException {
        // 指定配置文件
        String resource = ;mybatis-config.xml;;
        // 读取配置文件
        InputStream inputStream = Resources.getResourceAsStream(resource);
        // 构建sqlSessionFactory
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        // 获取sqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession(true);

        // 1. 映射文件的命名空间;namespace;必须是mapper接口的全路径
        // 2. 映射文件的statement的id必须和mapper接口的方法名保持一致
        // 3. Statement的resultType必须和mapper接口方法的返回类型一致
        // 4. statement的parameterType必须和mapper接口方法的参数类型一致;不一定;
        this.userMapper = sqlSession.getMapper(UserMapper.class);
    }


    ;Test
    public void login() {
        System.out.println(this.userMapper.login(;hj;, ;123456;));
    }

    ;Test
    public void queryUserByTableName() {
        List<User> userList = this.userMapper.queryUserByTableName(;tb_user;);
        for (User user : userList) {
            System.out.println(user);
        }
    }

    ;Test
    public void queryUserById() {
        System.out.println(this.userMapper.queryUserById(;1;));
    }

    ;Test
    public void queryUserAll() {
        List<User> userList = this.userMapper.queryUserAll();
        for (User user : userList) {
            System.out.println(user);
        }
    }

    ;Test
    public void insertUser() {
        User user = new User();
        user.setAge(20);
        user.setBirthday(new Date());
        user.setName(;大神;);
        user.setPassword(;123456;);
        user.setSex(2);
        user.setUserName(;bigGod222;);
        this.userMapper.insertUser(user);
        System.out.println(user.getId());
    }

    ;Test
    public void updateUser() {
        User user = new User();
        user.setBirthday(new Date());
        user.setName(;静静;);
        user.setPassword(;123456;);
        user.setSex(0);
        user.setUserName(;Jinjin;);
        user.setId(;1;);
        this.userMapper.updateUser(user);
    }

    ;Test
    public void deleteUserById() {
        this.userMapper.deleteUserById(;1;);
    }
}