SQL query. Very restricted due to environment. Is it even possible? - sql

Question

I'have a specific problem. I need get some some data from database. I have a mechanism to retrieve data from a program. I need to use it, no modifications possible. The original query is:
SELECT it_Symbol AS Symbol, tt_Name AS Nazwa, tt_Price AS Cena,
tt_Quantity AS Ilosc, tt_Id
FROM tr__Transaction INNER JOIN tr_Item
ON tt_TransId=tr_Id LEFT OUTER JOIN it__Item
ON tt_ItemId = it_Id RIGHT JOIN reg_Site
ON tr_SiteId = rs_Id LEFT OUTER JOIN it_ItemSite
ON it_Id = is_ItemId
WHERE tt_TransId=#transId
GROUP BY tt_Id, tt_Quantity, tr_Id, it_Name, tt_Price,it_Symbol,
is_Name, tt_Name, tt_ItemId, tt_Id
The problem is that I need to get some additional data from tr__Transaction table.
It has a field tr_Source. I need this fields value, but for tr__transaction records which have tr_Id listed in returned tt_Id field.
Any way to do a subquery returning values dependant on tt_Id column values?
Or maybe any other joins combination? I've spend whole week with this, and have no more ideas or skills to do this:/
Any help would be very appreciated.

Answer 1

Ok still don't know exactly what you need but it is an atempt to clean up the question. So this is a working version of the answer since you can't format code in comments.
Please explain if some relations are wrong.
you can always join tables multiple times under different conditions as long as they have different aliases.
For instance:
SELECT c.it_Symbol AS Symbol, a.tt_Name AS Nazwa, a.tt_Price AS Cena,
a.tt_Quantity AS Ilosc, a.tt_Id, f.tr_Source
FROM tr__Transaction a
INNER JOIN tr_Item b
ON a.tt_TransId=b.tr_Id
LEFT OUTER JOIN it__Item c
ON a.tt_ItemId = c.it_Id
RIGHT JOIN reg_Site d
ON a.tr_SiteId = d.rs_Id
LEFT OUTER JOIN it_ItemSite e
ON c.it_Id = e.is_ItemId
LEFT OUTER JOIN tr__Transaction f
ON c.tt_id = f.tr_id
WHERE a.tt_TransId=#transId
GROUP BY a.tt_Id, a.tt_Quantity, a.tr_Id, c.it_Name, a.tt_Price,c.it_Symbol,
e.is_Name, a.tt_Name, a.tt_ItemId, a.tt_Id

Answer 2

I'm not sure if I understand you question correctly, but assuming you are saying that the Original SQL statement cannot be changed (ie, it's in a read-only View). Then you can wrap it around another SELECT statement.
SELECT tblOriginal.*, tblExtend.tt_Source
FROM (
SELECT it_Symbol AS Symbol, tt_Name AS Nazwa, tt_Price AS Cena,
tt_Quantity AS Ilosc, tt_Id
FROM tr__Transaction INNER JOIN tr_Item
ON tt_TransId=tr_Id LEFT OUTER JOIN it__Item
ON tt_ItemId = it_Id RIGHT JOIN reg_Site
ON tr_SiteId = rs_Id LEFT OUTER JOIN it_ItemSite
ON it_Id = is_ItemId
WHERE tt_TransId=#transId
GROUP BY tt_Id, tt_Quantity, tr_Id, it_Name, tt_Price,it_Symbol,
is_Name, tt_Name, tt_ItemId, tt_Id
) AS tblOriginal
INNER JOIN tr__Transaction AS tblExtend
ON tblOriginal.tt_Id = tblExtend.tt_Id
But I suspect your problem is more complicated that that as you've spent over a week on it. In that case, can you elaborate?