Question

请帮我生成以下查询，我已经挣扎了一段时间了。让我们说我有一个简单的表格，其中包含月份数和信息，表明这个月是否有任何失败事件

在脚本下面生成样本数据：

WITH DATA(Month, Success) AS
(
    SELECT  1, 0 UNION ALL
    SELECT  2, 0 UNION ALL
    SELECT  3, 0 UNION ALL
    SELECT  4, 1 UNION ALL
    SELECT  5, 1 UNION ALL
    SELECT  6, 0 UNION ALL
    SELECT  7, 0 UNION ALL
    SELECT  8, 1 UNION ALL
    SELECT  9, 0 UNION ALL
    SELECT 10, 1 UNION ALL
    SELECT 11, 0 UNION ALL
    SELECT 12, 1 UNION ALL
    SELECT 13, 0 UNION ALL
    SELECT 14, 1 UNION ALL
    SELECT 15, 0 UNION ALL
    SELECT 16, 1 UNION ALL
    SELECT 17, 0 UNION ALL
    SELECT 18, 0
)

鉴于“重复失败”的定义：

如果在任何6个月内至少4个月内发生事件失败，那么这个失败的最后一个月是“重复失败”我的查询应该返回以下输出

Month   Success RepeatedFailure
1       0   
2       0   
3       0   
4       1   
5       1   
6       0       R1
7       0       R2
8       1   
9       0   
10      1   
11      0       R3
12      1   
13      0   
14      1   
15      0   
16      1   
17      0
18      0       R1

其中：

R1 -1在第6个月重复失败（过去6个月失败4次）。
R2在第7个月重复失败（过去6个月失败4次）。
R3第3次重复失败，第11个月（过去6个月失败4次）。

R1 - 在第18个月第1次重复失败，因为重复失败应该在最近6个报告期内第一次发生新的重复失败时从头开始再次编号

重复失败是连续计算的，因为根据其编号，我必须应用适当的乘数：

第一次重复失败 - X2
第二次重复失败 - X4
第3次，多次重复失败-X5。

Answer 1

我确信这可以改进，但它确实有效。我们基本上做两次通过 - 第一次建立重复失败，第二次建立重复失败的种。请注意，Intermediate2绝对可以取消，我只是为了清晰起见而将其分开。所有代码都是一个语句，我的解释是交错的：

;WITH DATA(Month, Success) AS
-- assuming your data  as defined (with my edit)
,Intermediate AS 
(
SELECT
    Month,
    Success,
    -- next column for illustration only
    (SELECT SUM(Success) 
     FROM DATA hist 
     WHERE curr.Month - hist.Month BETWEEN 0 AND 5) 
        AS SuccessesInLastSixMonths,
    -- next column for illustration only
    6 - (SELECT SUM(Success) 
     FROM DATA hist 
     WHERE curr.Month - hist.Month BETWEEN 0 AND 5) 
        AS FailuresInLastSixMonths,
    CASE WHEN 
            (6 - (SELECT SUM(Success) 
                    FROM DATA hist 
                    WHERE curr.Month - hist.Month BETWEEN 0 AND 5)) 
            >= 4 
            THEN 1
            ELSE 0 
    END AS IsRepeatedFailure
FROM DATA curr 
-- No real data until month 6
WHERE curr.Month > 5
)

此时，我们已经确定，每个月，它是否是一次重复失败，通过计算六个月内的失败直至并包括它。

,Intermediate2 AS
(
SELECT 
    Month,
    Success,
    IsRepeatedFailure,
    (SELECT SUM(IsRepeatedFailure) 
        FROM Intermediate hist 
        WHERE curr.Month - hist.Month BETWEEN 0 AND 5) 
        AS RepeatedFailuresInLastSixMonths
FROM Intermediate curr
)

现在我们已经计算了到现在为止的六个月中重复失败的次数

SELECT
    Month,
    Success,
    CASE IsRepeatedFailure 
        WHEN 1 THEN 'R' + CONVERT(varchar, RepeatedFailuresInLastSixMonths) 
        ELSE '' END
    AS RepeatedFailureText
FROM Intermediate2

所以我们可以说，如果这个月是一次又一次的失败，那么重复失败的基数是什么。

结果：

Month       Success     RepeatedFailureText
----------- ----------- -------------------------------
6           0           R1
7           0           R2
8           1           
9           0           
10          1           
11          0           R3
12          1           
13          0           
14          1           
15          0           
16          1           
17          0           
18          0           R1

(13 row(s) affected)

性能考虑取决于您实际拥有的数据量。

Answer 2

;WITH DATA(Month, Success) AS
(
    SELECT  1, 0 UNION ALL
    SELECT  2, 0 UNION ALL
    SELECT  3, 0 UNION ALL
    SELECT  4, 1 UNION ALL
    SELECT  5, 1 UNION ALL
    SELECT  6, 0 UNION ALL
    SELECT  7, 0 UNION ALL
    SELECT  8, 1 UNION ALL
    SELECT  9, 0 UNION ALL
    SELECT 10, 1 UNION ALL
    SELECT 11, 0 UNION ALL
    SELECT 12, 1 UNION ALL
    SELECT 13, 0 UNION ALL
    SELECT 14, 1 UNION ALL
    SELECT 15, 0 UNION ALL
    SELECT 16, 1 UNION ALL
    SELECT 17, 0 UNION ALL
    SELECT 18, 0
)

SELECT DATA.Month,DATA.Success,Isnull(convert(Varchar(10),b.result),'') +         
Isnull(CONVERT(varchar(10),b.num),'') RepeatedFailure
FROM (
SELECT *, ROW_NUMBER() over (order by Month) num FROM 
( Select * ,(case  when (select sum(Success) 
from DATA where MONTH>(o.MONTH-6) and MONTH<=(o.MONTH)  ) <= 2 
and o.MONTH>=6 then 'R' else  '' end) result
from DATA o
) a where result='R'
) b 
right join DATA on DATA.Month = b.Month
order by DATA.Month

使用排名函数查找重复出现的事件

2 个答案: