SQL - 如何为每行和每块标记编号
SQL - How to Label Number for Each ROW & BLOCK
我有一个 table 这样的专栏
A, A, B, C, A, A, B, D, E, E, E
我想像这样为每个行和块标记编号
(A, 1), (A, 1), (B, 2), (C, 3), (A, 4), (A, 4), (B, 5), (D, 6), (E, 7), (E, 7), (E, 7)
怎么办?谢谢。
假设你有这样的table:
SELECT * FROM t ORDER BY ord
let, ord
--------
A, 1
A, 2
B, 3
C, 4
A, 5
A, 6
B, 7
D, 8
E, 9
E, 10
E, 11
如果你这样做:
with cte as(
select let, ord, case when lag(let) over(order by ord) <> let then 1 else 0 end as letchanged
from yourtable
)
select let,
1 + sum(letchanged) over(order by ord rows unbounded preceding) as ctr
from cte
那么您将获得:
let, ctr
--------
A, 1
A, 1
B, 2
C, 3
A, 4
A, 4
B, 5
D, 6
E, 7
E, 7
E, 7
我有一个 table 这样的专栏
A, A, B, C, A, A, B, D, E, E, E
我想像这样为每个行和块标记编号
(A, 1), (A, 1), (B, 2), (C, 3), (A, 4), (A, 4), (B, 5), (D, 6), (E, 7), (E, 7), (E, 7)
怎么办?谢谢。
假设你有这样的table:
SELECT * FROM t ORDER BY ord
let, ord
--------
A, 1
A, 2
B, 3
C, 4
A, 5
A, 6
B, 7
D, 8
E, 9
E, 10
E, 11
如果你这样做:
with cte as(
select let, ord, case when lag(let) over(order by ord) <> let then 1 else 0 end as letchanged
from yourtable
)
select let,
1 + sum(letchanged) over(order by ord rows unbounded preceding) as ctr
from cte
那么您将获得:
let, ctr
--------
A, 1
A, 1
B, 2
C, 3
A, 4
A, 4
B, 5
D, 6
E, 7
E, 7
E, 7