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