使用递归 CTE 处理日期逻辑

Question

在工作中，我的一项任务是计算销售人员的佣金。一项规则比其他规则更具挑战性。

两个销售团队 A 和 B 一起工作，各自销售不同的产品。 A 团队可以将潜在客户发送给 B 团队。同一个客户可能会被多次发送。首次向客户（例如潜在客户 1）* 发送佣金时，将向 A 团队中创建潜在客户的销售人员支付佣金。现在，客户在接下来的 365 天内被“锁定”（从创建线索 1 的日期算起）。这意味着在此期间，没有人可以通过发送额外的线索为该客户获得额外的佣金（例如，线索 2 和 3 没有佣金）。 365 天到期后。可以创建新的潜在客户并获得佣金（例如潜在客户 4）。然后，从创建线索 4 之日算起，客户再次被锁定 365 天。因此，lead 5 没有佣金。棘手的部分是重置计算 365 天的日期。

'* 引用表#LEADS 和#DISERED 结果。

我已经使用游标解决了 tSQL 中的问题，但我想知道是否可以使用递归 CTE。我做了几次尝试，最好的一个贴在下面。我的解决方案的问题是，我不止一次引用递归表。我试图通过在 CTE 中嵌套 CTE 来解决这个问题。这是不允许的。我曾尝试在 CTE 中使用一个临时表，这也是不允许的。我尝试了几次重新编码 CTE 的递归部分，以便递归表只被引用一次，但是我无法让逻辑工作。

我正在使用 SQL 2008

IF OBJECT_ID('tempdb.dbo.#LEADS', 'U') IS NOT NULL
DROP TABLE #LEADS;

CREATE TABLE #LEADS (LEAD_ID INT, CUSTOMER_ID INT, LEAD_CREATED_DATE DATETIME, SALESPERSON_NAME varchar(20))
INSERT INTO #LEADS
VALUES   (1,    1,  '2013-09-01', 'Rasmus')
        ,(2,    1,  '2013-11-01', 'Christian')
        ,(3,    1,  '2014-01-01', 'Nadja')
        ,(4,    1,  '2014-12-24', 'Roar')
        ,(5,    1,  '2015-12-01', 'Kristian')
        ,(6,    2,  '2014-01-05', 'Knud')
        ,(7,    2,  '2015-01-02', 'Rasmus')
        ,(8,    2,  '2015-01-08', 'Roar')
        ,(9,    2,  '2016-02-05', 'Kristian')
        ,(10,   2,  '2016-03-05', 'Casper')

SELECT  *
FROM    #LEADS;

IF OBJECT_ID('tempdb.dbo.#DISERED_RESULT', 'U') IS NOT NULL
DROP TABLE #DISERED_RESULT;

CREATE TABLE #DISERED_RESULT (LEAD_ID INT, DESIRED_COMMISION_RESULT CHAR(3))
INSERT INTO #DISERED_RESULT
VALUES   (1, 'YES')
        ,(2, 'NO')
        ,(3, 'NO')
        ,(4, 'YES')
        ,(5, 'NO')
        ,(6, 'YES')
        ,(7, 'NO')
        ,(8, 'YES')
        ,(9, 'YES')
        ,(10, 'NO')

    SELECT  *
    FROM    #DISERED_RESULT;

WITH COMMISSION_CALCULATION AS
(
    SELECT  T1.*
            ,COMMISSION = 'YES'
            ,MIN_LEAD_CREATED_DATE AS COMMISSION_DATE
    FROM     #LEADS AS T1
    INNER JOIN  (
                SELECT  A.CUSTOMER_ID
                        ,MIN(A.LEAD_CREATED_DATE) AS MIN_LEAD_CREATED_DATE
                FROM    #LEADS AS A
                GROUP BY A.CUSTOMER_ID
                ) AS T2 ON T1.CUSTOMER_ID = T2.CUSTOMER_ID  AND T1.LEAD_CREATED_DATE = T2.MIN_LEAD_CREATED_DATE

UNION ALL

SELECT  T10.LEAD_ID
        ,T10.CUSTOMER_ID
        ,T10.LEAD_CREATED_DATE
        ,T10.SALESPERSON_NAME
        ,T10.COMMISSION
        ,T10.COMMISSION_DATE
FROM    (SELECT ROW_NUMBER() OVER(PARTITION BY T5.CUSTOMER_ID ORDER BY T5.LEAD_CREATED_DATE ASC) AS RN 
                ,T5.*
                ,T6.MAX_COMMISSION_DATE
                ,DATEDIFF(DAY, T6.MAX_COMMISSION_DATE, T5.LEAD_CREATED_DATE) AS ANTAL_DAGE_SIDEN_SIDSTE_COMMISSION
                ,CASE 
                    WHEN DATEDIFF(DAY, T6.MAX_COMMISSION_DATE, T5.LEAD_CREATED_DATE) > 365      THEN 'YES'
                    ELSE 'NO'
                END AS COMMISSION
                ,CASE 
                    WHEN DATEDIFF(DAY, T6.MAX_COMMISSION_DATE, T5.LEAD_CREATED_DATE) > 365      THEN T5.LEAD_CREATED_DATE
                    ELSE NULL
                END AS COMMISSION_DATE
        FROM        #LEADS AS T5
            INNER JOIN (SELECT      T4.CUSTOMER_ID
                                    ,MAX(T4.COMMISSION_DATE) AS MAX_COMMISSION_DATE
                        FROM        COMMISSION_CALCULATION AS T4
                        GROUP BY    T4.CUSTOMER_ID) AS T6   ON T5.CUSTOMER_ID = T6.CUSTOMER_ID
        WHERE   T5.LEAD_ID   NOT IN (SELECT LEAD_ID FROM COMMISSION_CALCULATION)
        ) AS T10
WHERE   RN = 1


)   
    SELECT  *
    FROM    COMMISSION_CALCULATION; 

Answer 1

我做了一些假设，您的描述并不完全有意义，但以下实现了您想要的结果：

if object_id('tempdb.dbo.#leads', 'u') is not null
drop table #leads;

create table #leads (lead_id int, customer_id int, lead_created_date datetime, salesperson_name varchar(20))
insert into #leads
values (1,    1,  '2013-09-01', 'rasmus')
      ,(2,    1,  '2013-11-01', 'christian')
      ,(3,    1,  '2014-01-01', 'nadja')
      ,(4,    1,  '2014-12-24', 'roar')
      ,(5,    1,  '2015-12-01', 'kristian')
      ,(6,    2,  '2014-01-05', 'knud')
      ,(7,    2,  '2015-01-02', 'rasmus')
      ,(8,    2,  '2015-01-08', 'roar')
      ,(9,    2,  '2016-02-05', 'kristian')
      ,(10,   2,  '2016-03-05', 'casper')

if object_id('tempdb.dbo.#disered_result', 'u') is not null
drop table #disered_result;

create table #disered_result (lead_id int, desired_commision_result char(3))
insert into #disered_result
values (1, 'yes'),(2, 'no'),(3, 'no'),(4, 'yes'),(5, 'no'),(6, 'yes'),(7, 'no'),(8, 'yes'),(9, 'yes'),(10, 'no')

with rownum
as
(
    select row_number() over (order by customer_id, lead_created_date) as rn                                -- This is to ensure an incremantal ordering id
            ,lead_id
            ,customer_id
            ,lead_created_date
            ,salesperson_name
    from #leads
)
,cte
as
(
    select rn
            ,lead_id
            ,customer_id
            ,lead_created_date
            ,salesperson_name
            ,'yes' as commission_result
            ,lead_created_date as commission_window_start
    from rownum
    where rn = 1

    union all

    select r.rn
            ,r.lead_id
            ,r.customer_id
            ,r.lead_created_date
            ,r.salesperson_name

            ,case when r.customer_id <> c.customer_id       -- If the customer ID has changed, we are at a new commission window.
                then 'yes'
                else case when r.lead_created_date > dateadd(d,365,c.commission_window_start)   -- This assumes the window is 365 days and not one year (ie. Leap years don't add a day)
                        then 'yes'
                        else 'no'
                        end
                end as commission_result

            ,case when r.customer_id <> c.customer_id
                then r.lead_created_date
                else case when r.lead_created_date > dateadd(d,365,c.commission_window_start)   -- This assumes the window is 365 days and not one year (ie. Leap years don't add a day)
                        then r.lead_created_date
                        else c.commission_window_start
                        end
                end as commission_window_start

    from rownum r
        inner join cte c
            on(r.rn = c.rn+1)
)
select lead_id
        ,commission_result
from cte
order by customer_id
        ,lead_created_date;