<resultMap type="主类" id="Result">
        <result property="id"    column="id"    />
        <result property="userAccount"    column="user_account"    />
        <result property="userLevel"    column="user_level"    />
        <result property="userName"    column="user_name"    />
        <result property="portrait"    column="portrait"    />
        <result property="coin"        column="coin"       />
    </resultMap>

    <select id="调用方法" parameterType="String"  resultMap="Result">
        SELECT
        a.id,
        a.user_account,
        a.user_level,
        a.user_name,
        a.portrait,
        t.coin
        FROM
        ud_users a
        LEFT JOIN (select user_id,sum(coin) as coin from 表 GROUP BY user_id)t on a.id=t.user_id where a.id in
        <foreach item="id" collection="array" open="(" separator="," close=")">
            #{id}
        </foreach>
    </select>