<?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 namespace="com.casic.dao.DeviceMapper">

    <select id="getWellCode" resultType="java.util.Map">
        select bd.id as "deviceId", bwi.WELL_CODE AS "wellCode"
        FROM (SELECT *
              FROM bus_device_well
              WHERE VALID = 1
        ) bdw
        JOIN (SELECT id
            FROM bus_device
            WHERE devcode = #{devcode}
            AND VALID = 1) bd ON bd.id = bdw.device_id
        JOIN(SELECT *
             FROM bus_well_info
             WHERE VALID = 1) bwi ON bwi.id = bdw.well_id
    </select>

</mapper>