Count() where the item counted is a JOIN back to another table - sql

Question

I'm pretty sure I could have done a better job with the title of this post. I wasn't sure how to shrink this question down into a working title...
I have two tables. BillItems and SubItems.
SubItems:
SubItemId ItemId MasterItemId
-----------------------------------
1 50 10
2 50 11
3 60 10
4 60 12
5 70 10
BillItems:
BillItemId ItemId
---------------------
1 10
2 11
3 50
4 60
5 70
Ok, so now, I need to know if BillItems contains any items that are chilren to more than one MasterItem, where the MasterItem is also inside of the BillItems table. I know that sounds confusing, so I'll give an example:
Item 50 is a child item to both Item 10 and Item 11. Item 10 and Item 11 are both in the BillItems table. So, I need Item 50 to show up in the query.
Item 60 is a child to both Item 10 and Item 12. Item 10 is in the BillItems table, but Item 12 is not. So I don't want Item 60 to show up in the query.
Items 10 and 11 are not children in SubItems. So I don't want it to show up in the query.
EDIT:
The desired output, with the above data, would be simply:
ItemId
------
50

Answer 1

I believe this is what you're looking for:
SELECT si.ItemId
FROM SubItems si
WHERE EXISTS (SELECT 1 -- This EXISTS may be omitted if SubItems.ItemId has an enforced FOREIGN KEY reference to BillItems.ItemId
FROM BillItems bi
WHERE bi.ItemId = si.ItemId)
AND EXISTS (SELECT 1
FROM BillItems bi
WHERE bi.ItemId = si.MasterItemId)
GROUP BY si.ItemId
HAVING COUNT(DISTINCT si.MasterItemId) > 1;

Answer 2

You can use a correlated sub-query to check if a masteritemid is present in the billitems table. For id's that aren't present you get a count of 0. You can then group by the itemid and eliminate all such items where there is a missing item and when there are more than 1 items in the itemid group.
select itemid
from (select itemid,(select count(*) from billitems where s.masteritemid=itemid) as present_or_not
from subitems s
) x
group by itemid
having count(case when present_or_not=0 then 1 end)=0 and count(*) > 1

Answer 3

You could do something like this:
var result=from b in context.BillItems
let masters=context.SubItems.Where(s=>s.ItemId==b.ItemId).Select(s=>s.MasterItemId)
where masters.All(e=>context.BillItems.Any(x=>x.ItemId==e))
select b.ItemId;
I noticed later this is a sql question :), but #Casey wants to look how to this in Linq. Another solution (in case you use EF and nav properties) could be:
var result=context.BillItems.Where(b=>b.SubItems.All(s=>context.BillItems.Any(x=>x.ItemId==s.MasterItemId))
.Select(e=>e.ItemId);
Or also doing a group join:
var result=from b in context.BillItems
join s in context.SubItems on b.ItemId equals s.ItemId into g
where g.All(e=>context.BillItems.Any(x=>x.ItemId==e.MasterItemId))
select b.ItemId;

Answer 4

Hoping I understood your question correctly.
Please check below query
select a.ItemId ItemId_a
--, count(distinct a.MasterItemId) , count(distinct b.ItemId)
from SubItems a left join BillItems b
on a.MasterItemId = b.ItemId
group by a.ItemId
having count(distinct a.MasterItemId) = count(distinct b.ItemId)
and count(distinct a.MasterItemId)>1
;

Answer 5

My two cents:
/*
create table BillItems (BillItemId int, ItemId int)
create table Subitems (SubitemId int, ItemId int, MasterItemId int)
insert BillItems values (1,10)
insert BillItems values (2,11)
insert BillItems values (3,50)
insert BillItems values (4,60)
insert BillItems values (5,70)
insert Subitems values(1,50,10)
insert Subitems values(2,50,11)
insert Subitems values(3,60,10)
insert Subitems values(4,60,12)
insert Subitems values(5,70,10)
*/
;with x as (select itemId from subitems group by itemId having count(*) > 1)
, y as (select s.ItemId, b.BillItemId from x join subitems s on x.itemid = s.itemid left join Billitems b on s.MasterItemId = b.ItemID)
select distinct itemid from y
except
select itemid from y where billitemid is null

Answer 6

You need something like this:
SELECT * FROM
(SELECT DISTINCT ItemId FROM TABLE1 t WHERE t.MasterId IN (SELECT ItemId FROM TABLE2)) as MasterInTable2
EXCEPT
(SELECT DISTINCT ItemId FROM TABLE1 t WHERE t.MasterId NOT IN (SELECT ItemId FROM TABLE2)) as
MasterNotInTable2

Answer 7

CREATE TABLE #SubItems (
id INT IDENTITY(1,1),
subItemID INT,
ItemID INT,
MasterItemID INT
)
INSERT INTO #SubItems
VALUES(1,50,10)
INSERT INTO #SubItems
VALUES(2,50,11)
INSERT INTO #SubItems
VALUES(3,60,10)
INSERT INTO #SubItems
VALUES(4,60,12)
INSERT INTO #SubItems
VALUES(5,70,10)
CREATE TABLE #BillItems (
id INT IDENTITY(1,1),
BillItemID INT,
ItemID INT
)
INSERT INTO #BillITems
VALUES(1,10)
INSERT INTO #BillITems
VALUES(2,11)
INSERT INTO #BillITems
VALUES(3,50)
INSERT INTO #BillITems
VALUES(4,60)
INSERT INTO #BillITems
VALUES(5,70)
SELECT A.ItemID
FROM (
SELECT bi.ItemID, COUNT(*) AS CountBill
FROM #BillItems bi
JOIN #SubItems si ON
bi.ItemID = si.ItemID
GROUP BY bi.ItemID
) A
JOIN #SubItems si ON
A.ItemID = si.ItemID
WHERE si.MasterItemID IN (SELECT ItemID FROM #BillItems)
GROUP BY A.ItemID
HAVING COUNT(*) > 1
DROP TABLE #SubItems
DROP TABLE #BillItems