选择最近的记录（带有到期日期）

Question

假设我们有 2 个名为 Records 和 Opportunities 的表：

记录：

RecordID	CustomerID	CreateDate
777	1	1/1/2021
888	2	1/1/2021
999	1	2/1/2021

机会：

OppID	CustomerID	OppCreateDate
10	1	12/31/2020
11	1	1/10/2021
12	2	2/1/2021
13	1	4/1/2021
14	1	8/5/2025

期望的输出：

RecordID	CustomerID	CreateDate	#Opportunities
777	1	1/1/2021	1
888	2	1/1/2021	1
999	1	2/1/2021	1

如您所见，Records 表提供了所需输出的前 3 列，而“#Opportunities”列是通过计算在创建记录之后发生的机会数创建的对于给定的客户。

关于这个逻辑需要注意两点：

1. 仅计算在记录后 6 个月内发生的机会。
2. 如果为客户创建了另一条记录，则只计算最近记录的机会。

更具体地说，OppID = 11 将记入 RecordID = 777； 12 至 888；和 13 到 999。10 和 14 不会记入任一 RecordID。

我写了下面的代码，没有考虑到上面的#2：

CREATE TABLE #Records
(
RecordID int
, CustomerID int
, CreateDate Date
)

INSERT INTO #Records
VALUES 
(777, 1, '2021-01-01')
, (888, 2, '2021-01-31')
, (999, 1, '2021-02-01')


CREATE TABLE #Opportunities
(
OppID int
, CustomerID int
, OppCreateDate Date
)

INSERT INTO #Opportunities
VALUES 
(10, 1, '2020-12-31')
, (11, 1, '2021-01-10')
, (12, 2, '2021-02-01')
, (13, 1, '2021-04-01')
, (14, 1, '2025-08-25')

select * 
from #Records

select * 
from #Opportunities

select rec.*
, (select count(*)
from #Opportunities opp
where rec.CustomerID=opp.CustomerID
and rec.CreateDate<=opp.OppCreateDate --record happened on the same day or before the opportunity
and datediff(month,rec.CreateDate,opp.OppCreateDate) < 6 --opened and created within 6 months
) as [#Opportunities]
from #Records rec

有什么建议可以合并上面的 #2 并生成所需的输出？

Answer 1

根据#records.CreateDate 确定哪个#records 行与#Opportunities 行相关

select RecordID, CustomerID, CreateDate, count(*) cnt
from (
   select r.RecordID, r.CustomerID, r.CreateDate,
      row_number() over(partition by op.OppID  order by r.CreateDate desc) rn
   from #records r
   join #Opportunities op on r.CustomerID = op.CustomerID and datediff(month, r.CreateDate, op.OppCreateDate) < 6 and r.CreateDate <= op.OppCreateDate
   ) t
where rn = 1 
group by RecordID, CustomerID, CreateDate

返回

RecordID    CustomerID  CreateDate  cnt
777 1   2021-01-01  1
888 2   2021-01-31  1
999 1   2021-02-01  1

Answer 2

试试这个：

DECLARE @Records table ( RecordID int, CustomerID int, CreateDate date );
INSERT INTO @Records VALUES 
    ( 777, 1, '2021-01-01' ), ( 888, 2, '2021-01-31' ), ( 999, 1, '2021-02-01' );


DECLARE @Opportunities table ( OppID int, CustomerID int, OppCreateDate date );
INSERT INTO @Opportunities VALUES 
      ( 10, 1, '2020-12-31' )
    , ( 11, 1, '2021-01-10' )
    , ( 12, 2, '2021-02-01' )
    , ( 13, 1, '2021-04-01' )
    , ( 14, 1, '2025-08-25' );

SELECT
    *
FROM @Records r
OUTER APPLY (

    SELECT
        COUNT ( * ) AS [#Opportunities]
    FROM @Opportunities AS o
    WHERE
        o.CustomerID = r.CustomerID
        AND o.OppCreateDate >= r.CreateDate
        AND DATEDIFF ( month, r.CreateDate, o.OppCreateDate ) <= 6
        AND o.OppID NOT IN (

            SELECT
                OppID
            FROM @Records AS r2 
            INNER JOIN @Opportunities AS o2
                ON r2.CustomerID = o2.CustomerID
            WHERE
                r2.CustomerID = o.CustomerID
                AND o2.OppCreateDate >= r2.CreateDate
                AND r2.RecordID > r.RecordID
        
        )

) AS Opps
ORDER BY
    r.RecordID;

返回

+----------+------------+------------+----------------+
| RecordID | CustomerID | CreateDate | #Opportunities |
+----------+------------+------------+----------------+
|      777 |          1 | 2021-01-01 |              1 |
|      888 |          2 | 2021-01-31 |              1 |
|      999 |          1 | 2021-02-01 |              1 |
+----------+------------+------------+----------------+