SQL View - Challenge - sql

Question

I have a small challenge trying to create a "work in progress view"
I'm not convinced my statement is the best or correct and resulted in an error "Subquery returned more than 1 value"
I have three key tables;
Tasks
PurchaseOrderItem
Resource
There is a unique reference field across all the tables e.g. Tasks.TA_SEQ, PurchaseOrderItem.TA_SEQ and Resource.TA_SEQ
I need to sum different totals from all these tables and the relationship are as follows;
1 Task - many PurchaseOrderItem
1 Task - many Resources
I need to sum all the Purchase order cost values (line items can vary) against active purchase orders for the Task and also sum all the resource cost (3 people - quantity can vary) against the task, any help would be much appreciated. if I can make it also any easier any advice would be appreciated.
Part of my Query as it stands;
SELECT
dbo.F_TASKS.TA_SEQ,
(
SELECT
SUM(POI_TOTAL)
From F_PO_ITEM
where POI_FKEY_TA_SEQ = dbo.F_TASKS.TA_SEQ
and POI_FKEY_POH_SEQ in
(
select
POH_SEQ
from F_PO_HEAD
where POH_STATUS in ('DORMANT', 'ACTIVE')
)
) AS [Pending PO Cost],
dbo.F_TASKS.TA_PO_COST AS [PO Cost],
dbo.F_TASKS.TA_LABOUR_COST AS [Labour Cost],
dbo.F_TASKS.TA_LABOUR_COST - SUM(dbo.F_TASK_TIME.TT_OTHER_COSTS) AS [New Labour Cost],
-----------Not Working from
(select
SUM(dbo.F_TASK_TIME.TT_OTHER_COSTS)
from F_TASK_TIME
where TT_FKEY_TA_SEQ = dbo.F_TASKS.TA_SEQ) + dbo.F_TASKS.TA_PO_COST AS [Subcontractor Costs],
(SUM(dbo.F_TASK_TIME.TT_OTHER_COSTS + dbo.F_TASKS.TA_PO_COST)) * 0.12 AS [Subcontractor Uplift],
((SUM(dbo.F_TASK_TIME.TT_OTHER_COSTS + dbo.F_TASKS.TA_PO_COST)) * 0.12) + (SUM(dbo.F_TASK_TIME.TT_OTHER_COSTS + dbo.F_TASKS.TA_PO_COST)) AS [Subcontractor Uplift Total]
-----------Not Working To
FROM dbo.F_TASKS
LEFT OUTER JOIN dbo.F_TASK_TIME
ON dbo.F_TASKS.TA_SEQ = dbo.F_TASK_TIME.TT_FKEY_TA_SEQ
LEFT OUTER JOIN dbo.F_PO_ITEM
ON dbo.F_TASKS.TA_SEQ = dbo.F_PO_ITEM.POI_FKEY_TA_SEQ
WHERE (dbo.F_TASKS.TA_TASK_DESC = 'BREAKDOWN')
AND (dbo.F_TASKS.TA_PO_COST >= 0)
AND (dbo.F_TASKS.TA_STATUS IN ('ACTIVE', 'ASSIGNED', 'COMPLETE'))
GROUP BY dbo.F_TASKS.TA_PO_COST, dbo.F_TASKS.TA_SEQ, dbo.F_TASKS.TA_LABOUR_COST

Answer 1

Rather than trying to fix your SQL, I'm going to propose a different wau of doing it. I couldn';t easily understand all the wheres in your selects in the select clause, so I've just done the first two.
This approach uses LEFT OUTER JOINs to queries which total by ta_seq. These are guaranteed to return only one row/ta_seq as that's how there're grouped:
SELECT
t.TA_SEQ,
isnull(po.poi_total, 0) [Pending PO Cost],
t.TA_PO_COST AS [PO Cost],
t.TA_LABOUR_COST AS [Labour Cost],
t.TA_LABOUR_COST - isnull(tt.other_costs, 0) AS [New Labour Cost],
-- other cols missed
FROM dbo.F_TASKS t
left outer join
(
t.ta_seq, SUM(POI_TOTAL) poi_total
From F_PO_ITEM poi
where POI_FKEY_POH_SEQ in
(
select
POH_SEQ
from F_PO_HEAD
where POH_STATUS in ('DORMANT', 'ACTIVE')
)
group by t.ta_seq
) po on po.ta_seq = t.ta_seq
left outer join
(
select tt.TT_FKEY_TA_SEQ ta_seq, sum(tt.tt_other_costs) other_costs
from F_TASK_TIME tt
group by tt.TT_FKEY_TA_SEQ
) tt on tt.ta_seq = t.ta_seq
WHERE (t.TA_TASK_DESC = 'BREAKDOWN')
AND (t.TA_PO_COST >= 0)
AND (t.TA_STATUS IN ('ACTIVE', 'ASSIGNED', 'COMPLETE'))
GROUP BY t.TA_PO_COST, t.TA_SEQ, t.TA_LABOUR_COST
I've also used table aliases as I find the schema.tablename format is making me blind (and not helping me decode the missed subqueries).
To put in the missing columns, just translate them into additional LEFT OUTER JOINs as above.
Cheers -