Sum Based on Grouping and Order - sql-server

Question

I have raw data similar to below ...
WO OP WC Time
1 10 Band Saw 2.0
1 15 Band Saw 5.0
1 17 Band Saw 10.0
1 20 CNC Lathe 6.0
1 22 Band Saw 102.0
1 30 Inspection 33.0
2 10 Band Saw 1.5
2 20 CNC Lathe 6.00
2 20 CNC Lathe 2.00
2 30 CNC Punch 0.5
2 40 Manual Ops 1.25
2 50 Inspection 0.00
I need it to Sum and Group like below. ie summing the Time for the WO/WC column until the WC changes, not a total for the overall WO. Hope I have explained that clearly enough (probably not)
We need to support SQL Server 2005.
WO WC Time
1 Band Saw 17.0
1 CNC Lathe 6.0
1 Band Saw 102.0
1 Inspection 33.0
2 Band Saw 1.5
2 CNC Lathe 8.00
2 CNC Punch 0.5
2 Manual Ops 1.25
2 Inspection 0.00

Answer 1

What about something like this. I build a row_number over the order you defined (WO and OP), Then, I build another row_number over each WC sorted by WO and OP. now you have two row_numbers. One over the entire set, and one over each WC. Now, when you subtract the latter from the former, you form groups wherever there is only 1 row difference, Each time there is MORe than one row, you get a new grouping. No recursion necessary.
;with t (WO, OP, WC, Time) as
(
select 1, 10, 'Band Saw', 2.0
union all select 1, 15, 'Band Saw', 5.0
union all select 1, 17, 'Band Saw', 10.0
union all select 1, 20, 'CNC Lathe', 6.0
union all select 1, 22, 'Band Saw', 102.0
union all select 1, 30, 'Inspection', 33.0
union all select 2, 10, 'Band Saw', 1.5
union all select 2, 20, 'CNC Lathe', 6.00
union all select 2, 20, 'CNC Lathe', 2.00
union all select 2, 30, 'CNC Punch', 0.5
union all select 2, 40, 'Manual Ops', 1.25
union all select 2, 50, 'Inspection', 0.00
), rn as
(
select
grp= row_number() over (order by WO, op) - row_number() over (partition by wo, wc order by wo, op),
*
from t
)
select grp, wo, wc, sum(time)
from rn
group by grp, wo, wc
Edited to use one cte. Also fixed the partition in the second order by. This outperforms an rcte with the data provided and will probably scale better because it doesnt have to recurse an arbitrary number of times.

Answer 2

Use a recursive CTE:
;WITH
cte1 AS
(
SELECT WO, OP, WC, Time,
ROW_NUMBER() OVER (ORDER BY WO, Op) AS RowNumber
FROM MyTable
),
cte2 AS
(
SELECT WO, OP, WC, Time, RowNumber,
1 AS GroupID
FROM cte1
WHERE RowNumber = 1
UNION ALL
SELECT cte1.WO, cte1.OP, cte1.WC, cte1.Time, cte1.RowNumber,
CASE
WHEN cte1.WC = cte2.WC THEN cte2.GroupID
ELSE cte2.GroupID + 1
END AS GroupID
FROM cte1
INNER JOIN cte2 ON cte1.RowNumber = cte2.RowNumber + 1
)
SELECT WO, WC, SUM(Time) As TotalTime
FROM cte2
GROUP BY GroupID, WO, WC
OPTION (MAXRECURSION 0)
I don't have SQL Server 2005 around to test but it should work. If you want more details, query cte1 and cte2.

Answer 3

Thanks to Xedni who supplied me with the bulk of the answer. I had to add the Max(op) and the sort to his supplied solution.
;with t (WO, OP, WC, Time) as
(
select 1, 10, 'Band Saw', 2.0
union all select 1, 15, 'Band Saw', 5.0
union all select 1, 17, 'Band Saw', 10.0
union all select 1, 20, 'CNC Lathe', 6.0
union all select 1, 22, 'Band Saw', 102.0
union all select 1, 30, 'Inspection', 33.0
union all select 2, 10, 'Band Saw', 1.5
union all select 2, 20, 'CNC Lathe', 6.00
union all select 2, 20, 'CNC Lathe', 2.00
union all select 2, 30, 'CNC Punch', 0.5
union all select 2, 40, 'Manual Ops', 1.25
union all select 2, 50, 'Inspection', 0.00
), rn as
(
select
grp= row_number() over (order by WO, op) - row_number() over (partition by wo, wc order by wo, op),
*
from t
)
select grp, wo, MAX(op) AS MaxOp, wc, sum(time)
from rn
group by grp, wo, wc
ORDER BY wo, MaxOp