Select most recent record (with expiration date) - sql

Question

Let's say that we have 2 tables named Records and Opportunities:
Records:
RecordID
CustomerID
CreateDate
777
1
1/1/2021
888
2
1/1/2021
999
1
2/1/2021
Opportunities:
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
Desired Output:
RecordID
CustomerID
CreateDate
#Opportunities
777
1
1/1/2021
1
888
2
1/1/2021
1
999
1
2/1/2021
1
As you can see, the Records table provides the first 3 columns of the desired output, and the "#Opportunities" column is created by counting the number of opportunities that happen after the record is created for a given customer.
Two key things to note on this logic:
Only count opportunities when they occur within 6 months of a record.
If another record is created for a customer, only count opportunities for the most recent record.
More specifically, OppID = 11 will get credited to RecordID = 777; 12 to 888; and 13 to 999. 10 and 14 will not get credited to either RecordID.
I wrote the below code, which does not take into account #2 above:
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
Any suggestions to incorporate #2 above and generate the desired output?

Answer 1

Decide on which #records row is related to an #Opportunities row based on #records.CreateDate
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
Returns
RecordID CustomerID CreateDate cnt
777 1 2021-01-01 1
888 2 2021-01-31 1
999 1 2021-02-01 1

Answer 2

Try this:
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;
RETURNS
+----------+------------+------------+----------------+
| RecordID | CustomerID | CreateDate | #Opportunities |
+----------+------------+------------+----------------+
| 777 | 1 | 2021-01-01 | 1 |
| 888 | 2 | 2021-01-31 | 1 |
| 999 | 1 | 2021-02-01 | 1 |
+----------+------------+------------+----------------+