select uid ,incomplete_cnt ,incomplete_rate from( select ui.uid ,level ,count(if(submit_time is null,start_time,null)) AS incomplete_cnt ,count(start_time) AS complete_cnt /*有作答记录,用start_time*/ ,round(if(count(start_time)=0,0,count(if(submit_time is null,start_time,null))/count(start_time)),3) AS in...