Compare field values from different users - sql

Question

Ok so this has been doing my head in for a while and the code has gone through a few different iterations.
I need to know if a technician has changed a time on service call and report a TRUE or FALSE statement.
Using the below example, the user of ID 60 IS NOT a technician and user 29 IS a technician.
We can see in log instance 10 that the technician (user 29) changed the time from the preexisting value that user id 60 had set (log instance 7) so this would report as TRUE. Otherwise, if there are no instances of changes by a technician I would instead need to return a false value.
Any other entries are irrelevant here, I just need to compare the start and end times from a technician with the last start and end time entries from a non-technician before hand (nothing afterwards).
If there are no entries by a technician it should still report a FALSE value.
A technician can be identified by the roleID of -2 on the HEM6 table which i have included. This query will become a subquery of a main query joined by the callID.
Apologies if this request is a bit wordy, happy to clarify if I can.
SELECT
T1.StartTime AS [Current start time],
T1.endTime AS 'Current End Time',
T2.LogInstanc,
T2.usersign2
FROM
ASC6 T1
INNER JOIN
ASCL T2 ON T2.LogInstanc = T1.[logInstanc]
AND T2.callID = T1.SrcvCallID
INNER JOIN
OUSR T3 ON T3.INTERNAL_K = T2.usersign2
INNER JOIN
OHEM T4 ON T4.userid = T3.userid
LEFT JOIN
HEM6 T5 ON T5.empID = T4.empID
WHERE
T1.srcvcallID = 25557
Results from this query:
Start Time
End Time
Log Instance
Updating User
8:54
9:09
2
1
15:30
16:00
3
60
15:30
16:00
4
60
15:30
16:30
5
60
15:30
17:00
6
60
15:30
16:30
7
60
15:30
16:30
8
29
15:30
16:30
9
29
15:45
16:45
10
29
15:45
16:45
11
29
15:45
16:45
12
60

Answer 1

Ok so i think i got this figured out, all the tests so far have implied it works.
SELECT COUNT(*)
FROM
(
SELECT
A.startTime AS [StartTime],
A.endTime AS [EndTime],
B.LogInstanc,
B.usersign2,
LAG(A.startTime,1) OVER(ORDER BY B.Loginstanc ASC) AS 'ChangedStartTime',
LAG(A.endTime,1) OVER(ORDER BY B.Loginstanc ASC) AS 'ChangedEndTime'
FROM ASC6 A
INNER JOIN ASCL B ON B.LogInstanc = A.[logInstanc] AND B.callID = A.SrcvCallID
INNER JOIN OUSR C ON C.INTERNAL_K = B.usersign2
INNER JOIN OHEM D ON D.userid = C.userid
LEFT JOIN HEM6 E ON E.empID = D.empID
WHERE A.srcvcallID = T0.callID AND
A.Technician <> 104 AND
A.Technician IS NOT NULL
)P
WHERE (P.StartTime <> P.ChangedStartTime OR P.endTime <> P.ChangedEndTime) AND
P.usersign2 IN (SELECT S.internal_k FROM OUSR S INNER JOIN OHEM X ON x.userid = s.userid INNER JOIN HEM6 T ON T.empID = X.empID WHERE T.roleID = -2)
GROUP BY P.loginstanc
ORDER BY P.loginstanc DESC
By using the LAG function i've offset the time to indicate where a change occured, as I only need to know if the technician changed the time i've excluded everyone else.
If the technician did change the time then it will display a 1 in the count, otherwise there is no results.