1、xml中这样写
<resultMap id="BaseResultMap" type="com.entity.AirMonitor" >
<result column="areaCode" property="areaCode" />
<result column="pm25" property="pm25" />
<result column="pm10" property="pm10" />
</resultMap>
<select id="getDayMap" parameterType="java.util.Date" resultMap="BaseResultMap">
SELECT
cast(avg(pm25) as decimal(18,2)) as pm25,
cast(avg(pm10) as decimal(18,2)) as pm10
area_code as areaCode
FROM t_air_day_monitor day
WHERE monitor_time = date(#{date})
GROUP BY point.area_code
</select>
2、mapper中:
@MapKey("areaCode")
Map<String,AirMonitorVo> getDayMap(Date date);
3、结果