//sql语句$sql="SELECT id,time,device_id,DATE_FORMAT(FROM_UNIXTIME(time),'%d') as date,ROUND(avg(ywh),2) as tywh,ROUND(avg(pm),2) as tpm,ROUND(avg(nmhc),2) as tnmhc FROM `sn_devicelog6`";//执行sql语句Db::execute($sql);