1. mybatis-config.xml

<?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>
    <!-- 配置mybatis執行環境 -->
    <environments default="development"
 
>
        <!-- 配置開發環境 -->
        <environment id="development">
            <!-- jdbc事務管理器 -->
            <transactionManager type="JDBC"/>
            <!-- 資料來源
             UNPOOLED 不適用連線池 即 每次請求都會為其建立一個DB連線，適用完畢後，會馬上將連線關閉
             POOLED 資料庫連線池來維護連線
             JNDI 資料來源可以定義到應用的外部，通過JDNI容器來獲取資料庫連線
             -->
 

            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mydb"/>
                <property name="username" value="mary"/>
                <property name
 
="password" value="11111"/>
            </dataSource>
        </environment>
        <!-- 可以多個環境切換。配置上線環境 -->
        <!--<environment id="online">-->
        <!--<transactionManager type="JDBC"/>-->
        <!--<dataSource type="POOLED">-->
        <!--<property name="driver" value="${jdbc.driverClass}"/>-->
        <!--<property name="url" value="${jdbc.url}"/>-->
        <!--<property name="username" value="${jdbc.username}"/>-->
        <!--<property name="password" value="${jdbc.password}"/>-->
        <!--</dataSource>-->
        <!--</environment>-->

    </environments>

    <!-- 對映器 -->
    <mappers>
        <!-- 註冊對映檔案 -->
        <mapper resource="mapper/FriendShipMapper.xml"/>
        <mapper resource="mapper/UserMapper.xml"/>
    </mappers>
</configuration>

2. UserMapper.xml

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="dao.UserMapper">
    <resultMap type="model.User" id="userMap">
        <id column="id" property="uid"/>
        <result column="user_name" property="user_name"/>
        <result column="password" property="password"/>
    </resultMap>

    <select id="saveUser" resultType="java.lang.Integer">
        insert into wechat.user(user_name, password)
        values (#{user_name}, #{password})
    </select>

    <select id="findUserByUid" resultMap="userMap">
        select user_name, password
        from user
        where uid = #{uid}
    </select>

    <select id="findUserByName" resultMap="userMap">
        select uid, password
        from user
        where user_name = #{user_name}
    </select>
</mapper>

2018-12-10