Datediff on 2 rows of a table with a condition - sql

Question

My data looks like the following
TicketID OwnedbyTeamT Createddate ClosedDate
1234 A
1234 A 01/01/2019 01/05/2019
1234 A 10/05/2018 10/07/2018
1234 B 10/04/2019 10/08/2018
1234 finance 11/01/2018 11/11/2018
1234 B 12/02/2018
Now, I want to calculate the datediff between the closeddates for teams A, and B, if the max closeddate for team A is greater than max closeddate team B. If it is smaller or null I don't want to see them. So, for example,I want to see only one record like this :
TicketID (Datediff)result-days
1234 86
and for another tickets, display the info. For example, if the conditions aren't met then:
TicketID (Datediff)result-days
2456 -1111111
Data sample for 2456:
TicketID OwnedbyTeamT Createddate ClosedDate
2456 A
2456 A 10/01/2019 10/05/2019
2456 B 08/05/2018 08/07/2018
2456 B 06/04/2019 06/08/2018
2456 finance 11/01/2018 11/11/2018
2456 B 12/02/2018
I want to see the difference in days between 01/05/2019 for team A, and
10/08/2018 for team B.
Here is the query that I wrote, however, all I see is -1111111, any help please?:
SELECT A.incidentid,
( CASE
WHEN Max(B.[build validation]) <> 'No data'
AND Max(A.crfs) <> 'No data'
AND Max(B.[build validation]) < Max(A.crfs) THEN
Datediff(day, Max(B.[build validation]), Max(A.crfs))
ELSE -1111111
END ) AS 'Days-CRF-diff'
FROM (SELECT DISTINCT incidentid,
Iif(( ownedbyteam = 'B'
AND titlet LIKE '%Build validation%' ), Cast(
closeddatetimet AS NVARCHAR(255)), 'No data') AS
'Build Validation'
FROM incidentticketspecifics) B
INNER JOIN (SELECT incidentid,
Iif(( ownedbyteamt = 'B'
OR ownedbyteamt =
'Finance' ),
Cast(
closeddatetimet AS NVARCHAR(255)), 'No data') AS
'CRFS'
FROM incidentticketspecifics
GROUP BY incidentid,
ownedbyteamt,
closeddatetimet) CRF
ON A.incidentid = B.incidentid
GROUP BY A.incidentid

Answer 1

I hope the following answer will be of help.
With two subqueries for the two teams (A and B), the max date for every Ticket is brought. A left join between these two tables is performed to have these information in the same row in order to perform DATEDIFF. The last WHERE clause keeps the row with the dates greater for A team than team B.
Please change [YourDB] and [MytableName] in the following code with your names.
--Select the items to be viewed in the final view along with the difference in days
SELECT A.[TicketID],A.[OwnedbyTeamT], A.[Max_DateA],B.[OwnedbyTeamT], B.[Max_DateB], DATEDIFF(dd,B.[Max_DateB],A.[Max_DateA]) AS My_Diff
FROM
(
--The following subquery creates a table A with the max date for every project for team A
SELECT [TicketID]
,[OwnedbyTeamT]
,MAX([ClosedDate]) AS Max_DateA
FROM [YourDB].[dbo].[MytableName]
GROUP BY [TicketID],[OwnedbyTeamT]
HAVING [OwnedbyTeamT]='A')A
--A join between view A and B to bring the max dates for every project
LEFT JOIN (
--The max date for every project for team B
SELECT [TicketID]
,[OwnedbyTeamT]
,MAX([ClosedDate]) AS Max_DateB
FROM [YourDB].[dbo].[MytableName]
GROUP BY [TicketID],[OwnedbyTeamT]
HAVING [OwnedbyTeamT]='B')B
ON A.[TicketID]=B.[TicketID]
--Fill out the rows on the max dates for the teams
WHERE A.Max_DateA>B.Max_DateB
You might be able to do with a PIVOT. I am leaving a working example.
SELECT [TicketID], "A", "B", DATEDIFF(dd,"B","A") AS My_Date_Diff
FROM
(
SELECT [TicketID],[OwnedbyTeamT],MAX([ClosedDate]) AS My_Max
FROM [YourDB].[dbo].[MytableName]
GROUP BY [TicketID],[OwnedbyTeamT]
)Temp
PIVOT
(
MAX(My_Max)
FOR Temp.[OwnedbyTeamT] in ("A","B")
)PIV
WHERE "A">"B"

Answer 2

Your sample query is quite complicated and has conditions not mentioned in the text. It doesn't really help.
I want to calculate the datediff between the closeddates for teams A, and B, if the max closeddate for team A is greater than max closeddate team B. If it is smaller or null I don't want to see them.
I think you want this per TicketId. You can do this using conditional aggregation:
SELECT TicketId,
DATEDIFF(day,
MAX(CASE WHEN OwnedbyTeamT = 'B' THEN ClosedDate END),
MAX(CASE WHEN OwnedbyTeamT = 'A' THEN ClosedDate END) as diff
)
FROM incidentticketspecifics its
GROUP BY TicketId
HAVING MAX(CASE WHEN OwnedbyTeamT = 'A' THEN ClosedDate END) >
MAX(CASE WHEN OwnedbyTeamT = 'B' THEN ClosedDate END)