mysql 根据总分排名 SELECT    t.*,    @rank := @rank + 1 AS rank FROM    ( SELECT @rank := 0 ) r,    (SELECT    tas.id,    tas.teacher_id,    tas.average,    tas.remark,    tas.create_time,    tas.course_id,    su.user_name,    ti.post,    ti.SUBJECT FROM    teacher_average_score tas    LEFT JOIN sys_user su ON tas.teacher_id = su.user_id    LEFT JOIN teacher_info ti ON tas.teacher_id = ti.user_id ORDER BY    tas.average DESC     ) AS t

mysql数据库查询表中相邻数据的差值

select a.time ,a.sum - b.sum sum,a.time,b.timefrom  (select @arownum:=@arownum+1 rownum,sum ,time from summary_hour,(select @arownum:=0) t where energy_type= 1 order by time) a,  (select @brownum:=@brownum+1 rownum ,sum,time from summary_hour,(select @brownum:=1) t where energy_type= 1 ORDEr by time) b  where a.rownum = b.rownum;