mysql按规律自动生成序号

[买买提子]

怎么按照品种分组，按日期排序，自动生成no这个字段

[LongRui888]

CREATE TABLE tb(pz NVARCHAR(10),jzyf DATE)

INSERT INTO tb
SELECT '毛笔','2014-05-03' UNION ALL
SELECT '毛笔','2014-12-08' UNION ALL
SELECT '毛笔','2014-07-26' UNION ALL

SELECT '钢笔','2014-08-12' UNION ALL
SELECT '钢笔','2014-12-23' UNION ALL
SELECT '钢笔','2015-02-09' UNION ALL
SELECT '钢笔','2014-10-30' UNION ALL
SELECT '钢笔','2014-11-08' UNION ALL

SELECT '铅笔','2014-04-13' UNION ALL
SELECT '铅笔','2014-05-18' UNION ALL
SELECT '铅笔','2014-08-26' UNION ALL
SELECT '铅笔','2014-10-18' UNION ALL
SELECT '铅笔','2014-12-08'

SELECT pz,jzyf,NO
FROM 
(
SELECT t.*,
       CASE WHEN @partition_by = t.pz THEN @rownum := @rownum + 1 
            ELSE @rownum :=1
	   END AS NO,
       @partition_by := pz AS partition_by
FROM tb t
INNER JOIN (SELECT @rownum :=0) r
        ON 1=1
INNER JOIN (SELECT @partition_by :='') p
        ON 1=1
ORDER BY t.pz,t.jzyf
)tb

[专注打酱油30年]

select pz, jzyf, rank
from (
select tt_tmp.pz, tt_tmp.jzyf, @rownum:=@rownum+1,if(@pjzyf=tt_tmp.jzyf, @rank:=@rank+1, @rank:=1) as rank, @pjzyf:= tt_tmp.pjzyf
from
(select pz, jzyf from pz, jzyf
from tt
ORDER BY pz asc,jzyf desc) tt_tmp,
(select @rownum := 0, @pjzyf := null, @rank:=0) a ) result;

[ACMAIN_CHM]

select pz,jzfy, (select count(*) from 怎么按照品种分组 where pz=t.pz and jzfy<=t.jzfy) as no from 怎么按照品种分组 t