SQL Server: calculate field data from fields in same table but different set of data
I was looking around and found no solution to this. I´d be glad if someone could help me out here:
I have a table, e.g. that has among others, following columns:
Vehicle_No, Stop1_depTime, Segment_TravelTime, Stop_arrTime, Stop_Sequence
The data might look something like this:
Vehicle_No Stop1_DepTime Segment_TravelTime Stop_Sequence Stop_arrTime
201 13000 60 1
201 13000 45 2
201 13000 120 3
201 13000 4
202 13300 240 1
202 13300 60 2
...
and I need to calculate the arrival time at each stop from the departure time at the first stop and the travel times in between for each vehicle. What I need in this case would look like this:
Vehicle_No Stop1_DepTime Segment_TravelTime Stop_Sequence Stop_arrTime
201 13000 60 1
201 13000 45 2 13060
201 13000 120 3 13105
201 13000 4 13225
202 13300 240 1
202 13300 60 2 13540
...
I have tried to find a solution for some time but was not successful - Thanks for any help you can give me!
Here is the query that still does not work - I am sure I did something wrong with getting the table from the database into this but dont know where. Sorry if this is a really simple error, I have just begun working with MSSQL.
Also, I have implemented the solution provided below and it works. At this point I mainly want to understand what went wrong here to learn about it. If it takes too much time, please do not bother with my question for too long. Otherwise - tha开发者_C百科nks a lot :)
;WITH recCTE
AS
(
SELECT ZAEHL_2011.dbo.L32.Zaehl_Fahrt_Id, ZAEHL_2011.dbo.L32.PlanAbfahrtStart, ZAEHL_2011.dbo.L32.Fahrzeit, ZAEHL_2011.dbo.L32.Sequenz, ZAEHL_2011.dbo.L32.PlanAbfahrtStart AS Stop_arrTime
FROM ZAEHL_2011.dbo.L32
WHERE ZAEHL_2011.dbo.L32.Sequenz = 1
UNION ALL
SELECT t. ZAEHL_2011.dbo.L32.Zaehl_Fahrt_Id, t. ZAEHL_2011.dbo.L32.PlanAbfahrtStart, t. ZAEHL_2011.dbo.L32.Fahrzeit,t. ZAEHL_2011.dbo.L32.Sequenz, r.Stop_arrTime + r. ZAEHL_2011.dbo.L32.Fahrzeit AS Stop_arrTime
FROM recCTE AS r
JOIN ZAEHL_2011.dbo.L32 AS t
ON t. ZAEHL_2011.dbo.L32.Zaehl_Fahrt_Id = r. ZAEHL_2011.dbo.L32.Zaehl_Fahrt_Id
AND t. ZAEHL_2011.dbo.L32.Sequenz = r. ZAEHL_2011.dbo.L32.Sequenz + 1
)
SELECT ZAEHL_2011.dbo.L32.Zaehl_Fahrt_Id, ZAEHL_2011.dbo.L32.PlanAbfahrtStart, ZAEHL_2011.dbo.L32.Fahrzeit, ZAEHL_2011.dbo.L32.Sequenz, ZAEHL_2011.dbo.L32.PlanAbfahrtStart,
CASE WHEN Stop_arrTime = ZAEHL_2011.dbo.L32.PlanAbfahrtStart THEN NULL ELSE Stop_arrTime END AS Stop_arrTime
FROM recCTE
ORDER BY ZAEHL_2011.dbo.L32.Zaehl_Fahrt_Id, ZAEHL_2011.dbo.L32.Sequenz
A recursive CTE solution - assumes that each Vehicle_No
appears in the table only once:
DECLARE @t TABLE
(Vehicle_No INT
,Stop1_DepTime INT
,Segment_TravelTime INT
,Stop_Sequence INT
,Stop_arrTime INT
)
INSERT @t (Vehicle_No,Stop1_DepTime,Segment_TravelTime,Stop_Sequence)
VALUES(201,13000,60,1),
(201,13000,45,2),
(201,13000,120,3),
(201,13000,NULL,4),
(202,13300,240,1),
(202,13300,60,2)
;WITH recCTE
AS
(
SELECT Vehicle_No, Stop1_DepTime, Segment_TravelTime,Stop_Sequence, Stop1_DepTime AS Stop_arrTime
FROM @t
WHERE Stop_Sequence = 1
UNION ALL
SELECT t.Vehicle_No, t.Stop1_DepTime, t.Segment_TravelTime,t.Stop_Sequence, r.Stop_arrTime + r.Segment_TravelTime AS Stop_arrTime
FROM recCTE AS r
JOIN @t AS t
ON t.Vehicle_No = r.Vehicle_No
AND t.Stop_Sequence = r.Stop_Sequence + 1
)
SELECT Vehicle_No, Stop1_DepTime, Segment_TravelTime,Stop_Sequence, Stop1_DepTime,
CASE WHEN Stop_arrTime = Stop1_DepTime THEN NULL ELSE Stop_arrTime END AS Stop_arrTime
FROM recCTE
ORDER BY Vehicle_No, Stop_Sequence
EDIT Corrected version of OP's query - note that it's not necessary to fully qualify the column names:
;WITH recCTE
AS
(
SELECT Zaehl_Fahrt_Id, PlanAbfahrtStart, Fahrzeit, L32.Sequenz, PlanAbfahrtStart AS Stop_arrTime
FROM ZAEHL_2011.dbo.L32
WHERE Sequenz = 1
UNION ALL
SELECT t.Zaehl_Fahrt_Id, t.PlanAbfahrtStart, t.Fahrzeit,t.Sequenz, r.Stop_arrTime + r.Fahrzeit AS Stop_arrTime
FROM recCTE AS r
JOIN ZAEHL_2011.dbo.L32 AS t
ON t.Zaehl_Fahrt_Id = r.Zaehl_Fahrt_Id
AND t.Sequenz = r.Sequenz + 1
)
SELECT Zaehl_Fahrt_Id, PlanAbfahrtStart, Fahrzeit, Sequenz, PlanAbfahrtStart,
CASE WHEN Stop_arrTime = PlanAbfahrtStart THEN NULL ELSE Stop_arrTime END AS Stop_arrTime
FROM recCTE
ORDER BY Zaehl_Fahrt_Id, Sequenz
I'm quite sure this works:
SELECT a.Vehicle_No, a.Stop1_DepTime,
a.Segment_TravelTime, a.Stop_Sequence, a.Stop1_DepTime +
(SELECT SUM(b.Segment_TravelTime) FROM your_table b
WHERE b.Vehicle_No = a.Vehicle_No AND b.Stop_Sequence < a.Stop_Sequence)
FROM your_table a
ORDER BY a.Vehicle_No
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