Question

I have the following query:

Select MAX("Counter") as "Counter", "DestinationId" FROM (          
 Select t1."Counter", t2.* From
           (SELECT "HierarchyNodeId", (SELECT "Description"
            FROM "Destination"
           WHERE "DestinationId" = hn."DestinationId") "Description", "DestinationId",
         (SELECT "DestinationTypeId"
            FROM "Destination"
           WHERE "DestinationId" = hn."DestinationId") "DestinationTypeId"
    FROM "HierarchyNode" hn
WHERE "DestinationId" IN (SELECT "DestinationId" From(SELECT COUNT ("HierarchyNodeId"), "DestinationId" FROM "HierarchyNode" GROUP BY "DestinationId" HAVING COUNT ("HierarchyNodeId") > 1))) t2, 
(select COUNT (*) "Counter", "HierarchyNodeId" From "HierarchyDetail"
Group By "HierarchyNodeId") t1
Where t1."HierarchyNodeId" = t2."HierarchyNodeId"
ORDER BY "DestinationId", "Counter" Desc
)
GROUP BY "DestinationId"

The output shows the Maximum Counter for each Destination ID.
The extra information that I need is the HierarchyId that corresponds to that Particular Row (With that specific Destination Id and Counter).

If I change it to:

Select MAX("Counter") as "Counter", "DestinationId", "HierarchyId" FROM ( ....

I get an error because I didn’t include HierarchyId in the Group By. But if I include a get the Max Counter for each combination of DestinationId – HierarchyId (not each DestinationId only).

So I tried this:

Select * From (
Select t1."Counter", t2.* From
           (SELECT "HierarchyNodeId", (SELECT "Description"
            FROM "Destination"
           WHERE "DestinationId" = hn."DestinationId") "Description", "DestinationId",
         (SELECT "DestinationTypeId"
            FROM "Destination"
           WHERE "DestinationId" = hn."DestinationId") "DestinationTypeId"
    FROM "HierarchyNode" hn
WHERE "DestinationId" IN (SELECT "DestinationId" From(SELECT COUNT ("HierarchyNodeId"), "DestinationId" FROM "HierarchyNode" GROUP BY "DestinationId" HAVING COUNT ("HierarchyNodeId") > 1))) t2, 
(select COUNT (*) "Counter", "HierarchyNodeId" From "HierarchyDetail"
Group By "HierarchyNodeId") t1
Where t1."HierarchyNodeId" = t2."HierarchyNodeId"
ORDER BY "DestinationId", "Counter" Desc
) test1
Inner Join
(
Select MAX("Counter") as "Counter", "DestinationId" FROM (          
 Select t1."Counter", t2.* From
           (SELECT "HierarchyNodeId", (SELECT "Description"
            FROM "Destination"
           WHERE "DestinationId" = hn."DestinationId") "Description", "DestinationId",
         (SELECT "DestinationTypeId"
            FROM "Destination"
           WHERE "DestinationId" = hn."DestinationId") "DestinationTypeId"
    FROM "HierarchyNode" hn
WHERE "DestinationId" IN (SELECT "DestinationId" From(SELECT COUNT ("HierarchyNodeId"), "DestinationId" FROM "HierarchyNode" GROUP BY "DestinationId" HAVING COUNT ("HierarchyNodeId") > 1))) t2, 
(select COUNT (*) "Counter", "HierarchyNodeId" From "HierarchyDetail"
Group By "HierarchyNodeId") t1
Where t1."HierarchyNodeId" = t2."HierarchyNodeId"
ORDER BY "DestinationId", "Counter" Desc
)
GROUP BY "DestinationId"
) test2
On test1."DestinationId" = test2."DestinationId"
And test1."Counter" = test2."Counter"

This one gives me 1456 records when the FIRST query gives me 1256…
But I only want 1 HierachyNodeId for each row of the first query. So it doesn’t make sense.
It should be 1256 rows.

Answer 1

Use keep dense_rank:

Select 
    MAX("Counter") as "Counter", 
    "DestinationId" 
    max("HierarchyId") keep (dense_rank first order by counter desc) as "HierarchyId"
FROM ( query)
GROUP BY "DestinationId";