This is the SQL database data:
UserTable
UserName | UserDate | UserCode
-------------------------------------------
user1 | 08-31-2014 | 232
user1 | 09-01-2014 | 232
user1 | 09-02-2014 | 0
user1 | 09-03-2014 | 121
user1 | 09-08-2014 | 122
user1 | 09-09-2014 | 0
user1 | 09-10-2014 | 144
user1 | 09-11-2014 | 166
user2 | 09-01-2014 | 177
user2 | 09-04-2014 | 188
user2 | 09-05-2014 | 199
user2 | 09-06-2014 | 0
user2 | 09-07-2014 | 155
Should only count consecutive days (as Result) if [UserCode] is something else than zero. UserDate is between 09-01-2014 and 09-11-2014. Show result only if Result is 2 or more.
What I want to my sql query to return is:
UserName | StartDate | EndDate | Result
----------------------------------------------------------
user1 | 09-01-2014 | 09-03-2014 | 2
user1 | 09-08-2014 | 09-11-2014 | 3
user2 | 09-04-2014 | 09-07-2014 | 3
Is this possible using only SQL query?
This is a Gaps and Islands problem. The easiest way to solve this is using ROW_NUMBER() to identify the gaps in the sequence:
SELECT UserName,
UserDate,
UserCode,
GroupingSet = DATEADD(DAY,
-ROW_NUMBER() OVER(PARTITION BY UserName
ORDER BY UserDate),
UserDate)
FROM UserTable;
This gives:
UserName | UserDate | UserCode | GroupingSet
------------+---------------+------------+-------------
user1 | 09-01-2014 | 1 | 08-31-2014
user1 | 09-02-2014 | 0 | 08-31-2014
user1 | 09-03-2014 | 1 | 08-31-2014
user1 | 09-08-2014 | 1 | 09-04-2014
user1 | 09-09-2014 | 0 | 09-04-2014
user1 | 09-10-2014 | 1 | 09-04-2014
user1 | 09-11-2014 | 1 | 09-04-2014
user2 | 09-01-2014 | 1 | 08-31-2014
user2 | 09-04-2014 | 1 | 09-02-2014
user2 | 09-05-2014 | 1 | 09-02-2014
user2 | 09-06-2014 | 0 | 09-02-2014
user2 | 09-07-2014 | 1 | 09-02-2014
As you can see this gives a constant value in GroupingSet for consecutive rows. You can then group by this colum to get the summary you want:
WITH CTE AS
( SELECT UserName,
UserDate,
UserCode,
GroupingSet = DATEADD(DAY,
-ROW_NUMBER() OVER(PARTITION BY UserName
ORDER BY UserDate),
UserDate)
FROM UserTable
)
SELECT UserName,
StartDate = MIN(UserDate),
EndDate = MAX(UserDate),
Result = COUNT(NULLIF(UserCode, 0))
FROM CTE
GROUP BY UserName, GroupingSet
HAVING COUNT(NULLIF(UserCode, 0)) > 1
ORDER BY UserName, StartDate;