Question

我有一张这样的表 -

C1   C2         C3
A   20130101    10
A   20130102    10
A   20130103    20
A   20130104    10

我想设置这样的行 -

C1   C2         C3   RowNo
A   20130101    10   1
A   20130102    10   2
A   20130103    20   1
A   20130104    10   1

如何通过查询制作？或者只有办法循环这个表？

谢谢..

Answer 1

我用递归CTE更新了答案。它构建层次结构树，从具有新C3值和显示级别为RowNo的记录开始。

with t as 
(select t.*, row_number () over (order by c2) rn from table1 t)

,temp (c2,c3,rn,lvl)  AS 
(SELECT c2,c3,rn,1 lvl from t t1  
                       where not exists(
                                        select 1 from t t0 
                                                 where t1.rn=t0.rn+1 
                                                   and t1.c3=t0.c3
                                       )
  UNION ALL 
 select t1.c2,t1.c3,t1.rn,lvl + 1 AS lvl FROM t t1
 join temp t2 on t1.rn=t2.rn+1 and t1.c3=t2.c3)

SELECT c2, c3, lvl rowno FROM temp order by rn;

http://sqlfiddle.com/#!3/4adbd/1

Answer 2

ROW_NUMBER（）函数可以帮助您设置行数：

SELECT ROW_NUMBER() over(order by [some field]), *
      FROM [your table]

Answer 3

SELECT ROW_NUMBER（）over（PARTITION BY [C3] order by [C2]），* 从表名

如何设置行号（）

3 个答案: