Row value inconsistency - sql

Question

Scenario -
We have pack items, which is defined as a composite of one or more items. A complex pack is a one that has more than one component items. Each component item of a complex pack item should be linked to equal number of locations.
For example:
Pack P1 has component C1, C2, and C3. Each item C1,C2 and C3 is ranged to 10 locations 1,2....10, such that C1-1,C1-2,...,C1-10,C2-1,C2-2,...,C2-10,and C3-1,C3-2,...,C3-10 exists. In such case the pack item P1 also gets associated to locations 1 through 10, as P1-1,P1-2,...,P1-10.
The table PACK_BREAKOUT contains the Pack component mapping and the table ITEM_LOCATION contains the items to location association. Both Pack and Component are considered as "items" and would exist in ITEM_LOCATION.
Ideally, for the a scenario like above the below record-set would be valid
PACK_NO ITEM NO_OF_LOC
-------- ------ -------------
P1 C1 10
P1 C2 10
P1 C3 10
I have the query below that returns result like above for all such pack items.
select c.pack_no,c.item,count(a.loc )
from item_location a, pack_breakout c
where c.item=a.item
group by c.pack_no,c.item
order by 1,2;
However, there are some discrepant results like pack no. P2 , P4, and P5 below where the components are not associated with equal number of locations.
PACK_NO ITEM NO_OF_LOC
-------- ------ -------------
P1 C1 10
P1 C2 10
P1 C3 10
P2 C1 11
P2 C2 5
P2 C3 9
P2 C4 11
P3 C1 21
P3 C2 21
P3 C3 21
P3 C4 21
P3 C5 21
P4 C1 10
P4 C2 15
P5 C1 10
P5 C2 9
P5 C3 10
P5 C4 10
Note that a pack can have n-number of components (as you can see P1, P2, P3, P4, and P5 have different number of components).
I would like to get only the packs whose component locations are not all consistent. So the desired result set would be-
PACK_NO ITEM NO_OF_LOC
-------- ------ -------------
P2 C1 11
P2 C2 5
P2 C3 9
P2 C4 11
P4 C1 10
P4 C2 15
P5 C1 10
P5 C2 9
P5 C3 10
P5 C4 10
Note that even if one component does not match no. of locations as the other components within the pack, the entire pack must be considered inconsistent (like P5).

Answer 1

You want to use another group by with a having clause:
select pack_no
from (select c.pack_no, c.item, count(a.loc ) as numlocs
from item_location a join
pack_breakout c
on c.item=a.item
group by c.pack_no, c.item
) p
group by pack_no
having MIN(numlocs) <> MAX(numlocs)
This returns the packs.
If you want the details of the numbers, then use the analytic functions for the calculation:
select pi.*
from (select pi.*, min(numlocs) over (partition by pack_no) as minnumlocs,
max(numlocs) over (partition by packno) as maxnumlocs
from (select c.pack_no, c.item, count(a.loc ) as numlocs
from item_location a join
pack_breakout c
on c.item=a.item
group by c.pack_no, c.item
) pi
) pi
where minnumlocs <> maxnumlocs