用于数据过滤的 Oracle SQL 函数或桶

Question

SELECT 
     transaction
    ,date
    ,mail
    ,status
    ,ROW_NUMBER() OVER (PARTITION BY mail ORDER BY date) AS rownum
FROM table1

有了上面的 table 和脚本，我希望能够根据前 3 个状态为 'failed' 的 rowid 来过滤交易，如果 'failed'，则显示 rowid 4，与 rowid 4,5,6 的事务失败 - 如果也失败则显示 7 等。我正在考虑将它添加到 pandas 数据框，其中运行一个简单的 lambda 函数，但真的很想找到仅 SQL 的解决方案。

Answer 1

试试这个：

select * from (
SELECT 
     transaction
    ,date
    ,mail
    ,status
    ,ROW_NUMBER() OVER (PARTITION BY mail ORDER BY date) AS rownum
FROM table1
WHERE status = 'FAILED' )
where mod(rownum, 3) = 1;

理查德

Answer 2

一种选择是使用 window 函数。使用 lag 获取先前的状态值（基于指定的排序）并将其与当前行的值进行比较，并使用运行总和分配组。然后计算每组中的值，最后筛选该条件。

SELECT t.*
FROM
  ( SELECT t.*,
           count(*) over(PARTITION BY mail, grp) AS grp_count
   FROM
     ( SELECT t.*,
              sum(CASE
                      WHEN (prev_status IS NULL AND status='FAILED') OR 
                           (prev_status='FAILED' AND status='FAILED') THEN 0
                      ELSE 1
                  END) over(PARTITION BY mail ORDER BY "date","transaction") AS grp
      FROM
        ( SELECT t.*,
                 lag(status) over(PARTITION BY mail ORDER BY "date","transaction") AS prev_status
         FROM tbl t 
        ) t 
     ) t 
 ) t
WHERE grp_count>=4

如果您使用的是从 Oracle 12c 开始的版本，可以选择使用 MATCH_RECOGNIZE 来简化这一过程。

select *
from tbl
MATCH_RECOGNIZE (
         PARTITION BY mail
         ORDER BY "date" ,"transaction"
         ALL ROWS PER MATCH
         AFTER MATCH SKIP TO LAST FAIL
         PATTERN(fail{4,})
         DEFINE 
         fail AS (status='FAILED')
       ) MR
ORDER BY "date","transaction"

Answer 3

您可以使用 lead() 和 lag() 明确检查：

select t.*
from (select t1.*,
             lag(status, 3) over (partition by mail order by date) as status_3,
             lag(status, 3) over (partition by mail order by date) as status_2,
             lag(status, 3) over (partition by mail order by date) as status_1,
             lead(status, 1) over (partition by mail order by date) as status_3n,
             lead(status, 2) over (partition by mail order by date) as status_2n,
             lead(status, 3) over (partition by mail order by date) as status_3n
      from t
     ) t
where status = 'FAILED' and
      ( (status_3 = 'FAILED' and status_2 = 'FAILED' and status_1 = 'FAILED') or
        (status_2 = 'FAILED' and status_1 = 'FAILED' and status_1n = 'FAILED') or
        (status_1 = 'FAILED' and status_1n = 'FAILED' and status_2n = 'FAILED') or
        (status_1n = 'FAILED' and status_2n = 'FAILED and status_3n = 'FAILED')
      )

这个有点暴力，不过我觉得逻辑还是挺清晰的

您可以将逻辑简化为：

where regexp_like(status_3 || status_2 || status_1 || status || status_1n || status_2n || status3n,
                  'FAILED{4}'
                 )

用于数据过滤的 Oracle SQL 函数或桶

Oracle SQL function or buckets for data filtering

sql

oracle

bucket

rownum