单表映射一对一

<mapper namespace="接口路径">
    <resultMap id="名称1" type="映射类名">

        <id column="id" property="id"/>
        <result column="user_id" property="userId"/>
        <result column="out_trade_no" property="outTradeNo"/>
        <result column="state" property="state"/>
        <result column="creat_time" property="creatTime"/>
        <result column="total_fee" property="totalFee"/>
        <result column="video_id" property="videoId"/>
        <result column="video_title" property="videoTitle"/>


        <!--association 配置属性一对一
            property 对应videoOrder里面的user属性名
            javaType 这个属性的类型
        -->
        <association property="user" javaType="User">
            <id property="id" column="user_id" jdbcType="INTEGER"/>
            <result property="name" column="name" jdbcType="VARCHAR"/>
            <result property="phone" column="phone" jdbcType="VARCHAR"/>
            <result property="headImg" column="head_img" jdbcType="VARCHAR"/>
            <result property="createTime" column="create_time" jdbcType="TIMESTAMP"/>
        </association>
    </resultMap>

    <select id="queryVideoOrderList" resultMap="名称1">

　　　　　　<!--sql语句-->
        select
        o.id,
        o.user_id,
        o.out_trade_no,
        o.state,
        o.create_time,
        o.total_fee,
        o.video_id,
        o.video_title,
        o.video_img,
        u.name,
        u.pwd,
        u.phone,
        u.create_time,
        u.head_img
        from video_order o left join user u on o.user_id = u.id

    </select>