计算连续零的数量及其实例 SQL

如何解决计算连续零的数量及其实例 SQL

数据如下：

Row_No    ID     Bal
1        01      0
2        01      0
3        01      0
4        01      10
5        01      0
6        01      0
7        01      20
8        01      0
9        02      30
10       02      0
11       02      40
12       02      10
13       02      0
14       02      25
15       02      0
16       02      0
17       02      0

实例 = 连续零的次数

count(consecutive_zeros) = 总零

对于 ID = 01：

实例：

实例 1： Row_No 1,2,3

实例 2： Row_No 5,6

计数（consecutive_zeros）：

例如没有 1，我们有 3 个零

例如没有 2 w 有 2 个零

总计 = 5

Row_no 8 不被考虑，因为它后面没有连续的零

所需输出

ID    instances    count(consecutive_zeros)
01    2            5 
02    1            3

解决方法

;为此，您可以使用lag()和lead()：

select id,sum(case when bal = 0 and (prev_bal = 0 or prev_bal is null) and
                     next_bal = 0
                then 1 else 0
            end) as instances,sum(case when bal = 0 and prev_bal = 0 then 1 else 0 end)
from (select t.*,lag(bal) over (partition by id order by row_no) as prev_bal,lead(bal) over (partition by id order by row_no) as next_bal
      from t
     ) t
group by id;

您不必将此视为间隙和孤岛问题。您的两个措施非常简单：

• instances 在值“更改”为 0 并且下一个值也是 0 时计数。
• count 计算值为 0 且下一个值为 0 的值。

,

这是一种解决方案：

• 按 Row_No 为每个 ID 订单编号
• 过滤掉余额 = 0 的行；此步骤将创建孤岛和间隙，例如对于 ID #1，您有 (1,2,3),(5,6) 和 (8)
• 给岛屿编号以进行分组
• 计算拥有不止一件物品的岛屿及其大小
• 根据需要对结果进行分组

WITH cte1 AS (
    SELECT *,ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Row_No) AS rn
    FROM t
),cte2 AS (
    SELECT *
    FROM cte1
    WHERE Bal = 0
),cte3 AS (
    SELECT *,rn - ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Row_No) AS grp
    FROM cte2
),cte4 AS (
    SELECT ID,grp,COUNT(*) AS grp_size
    FROM cte3
    GROUP BY ID,grp
    HAVING COUNT(*) > 1
)
SELECT ID,COUNT(*) AS instances,SUM(grp_size) AS total_size_of_groups
FROM cte4
GROUP BY ID

DB<>Fiddle

,

Gordin Linoff，您的回答近乎完美。但是，这将给出准确的结果：

select  id,BAL_CON_ZERO_INSTANCES+ (total_zeros-BAL_CON_ZERO_DAYS) AS BAL_CON_ZERO_INSTANCES,BAL_CON_ZERO_DAYS
(
select id,sum(case when bal = 0 and (prev_bal = 0 or prev_bal is null) and (next_bal = 1 or next_bal is null) 
                then 1 else 0
            end)  as BAL_CON_ZERO_INSTANCES,sum(case when (bal = 0 and (next_bal = 0 or next_bal is null) or (bal = 0 and (prev_bal = 0 or prev_bal is null) and (next_bal = 1 or next_bal is null))) then 1 else 0 end) as BAL_CON_ZERO_DAYS,sum(case when bal = 0 then 1 else 0 end) as total_zeros

from (select t.*,bal,lead(bal) over (partition by id order by row_no) as next_bal
      from t
     ) t
group by id;