SQL find exact record combination - sql

Question

I have two tables, one with routes and one with order delivery data.
I need to choose for each order exact route which has all shops in it, no more no less, order of shops is not important. If I don't have exact route, I don't want to join any route to that order.
RouteId ShopId
------------------------------------
1 111
1 222
2 111
2 222
2 333
3 111
3 222
3 333
3 444
OrderId ShopId
------------------------------------
11 111
11 222
11 333
12 111
12 222
13 111
13 333
I want result set like this
OrderId ShopId RouteId
------------------------------------
11 111 2
11 222 2
11 333 2
12 111 1
12 222 1
13 111 NULL
13 333 NULL
I have around 50k-100k orders so I don't want to use cursors or any other loop if not necessary.
Any help is greatly appreciated.
Zoran

Answer 1

You can use FOR XML PATH in order to get into a string value all shops per OrderId and per RouteId:
;WITH RoutesCTE AS (
SELECT RouteId,
(SELECT ShopId
FROM routes AS r2
WHERE r2.RouteId = r1.RouteId
ORDER BY ShopId
FOR XML PATH('')) AS RouteShops
FROM routes AS r1
GROUP BY RouteId
), OrdersCTE AS (
SELECT OrderId, ShopId,
(SELECT ShopId
FROM orders AS o2
WHERE o2.OrderId = o1.OrderId
ORDER BY ShopId
FOR XML PATH('')) AS OrderShops
FROM orders AS o1
)
SELECT OrderId, ShopId, c2.RouteId
FROM OrdersCTE AS c1
LEFT JOIN RoutesCTE AS c2 ON c1.OrderShops = c2.RouteShops
In the above CTEs RouteShops and OrderShops hold an XML value of all shops per RouteId and OrderId respectively.
So, for example, RoutesCTE returns the following results:
RouteId RouteShops
-----------------------------------------------------------------
1 <ShopId>111</ShopId><ShopId>222</ShopId>
2 <ShopId>111</ShopId><ShopId>222</ShopId><ShopId>333</ShopId>
3 <ShopId>111</ShopId><ShopId>222</ShopId><ShopId>333</ShopId><ShopId>444</ShopId>
Comparing these two fields we can find exact matches (if any).
Demo here
Note: The above query may return more than one route per OrderId if the routes table contains RouteIds having the same combination of ShopIds. In this case you have to fiddle with the RoutesCTE (including a ROW_NUMBER in it for example).

Answer 2

I like the xml answer from Giorgos better but I had started on this
select t1.*
from
(
select cteS.OrderID, cteR.RouteID, count(*) as count
from cteS
join cteR
on cteS.StoreID = cteR.StoreID
group by cteS.OrderID, cteR.RouteID
) t1
join
(
select cteS.OrderID, count(*) as count
from cteS
group by cteS.OrderID
) t2
on t1.OrderID = t2.OrderID
and t2.count = t2.count
or
select OrderID, RouteID
from store
join route
on store.storeID = route.storeID
except
select OrderID, RouteID
from store
full outer join route
on store.storeID = route.storeID
where store.storeID is null or route.storeID is null

Answer 3

Use of LEFT JOIN put to NULL fields of secondary table (RouteTable) is there's no corrispondence in JOIN clause.
Try this:
SELECT O.*, R.RouteId
FROM OrderTable O
LEFT OUTER JOIN RouteTable R
ON O.ShopId = R.ShopId