Query for Exploding all production orders needed to fulfil a sales order

Question

I am trying to write a query that explodes all the multiple levels BOMS and brings back a list of production orders that would need to be raised to fulfil a particular sales order.
SELECT T0.[DocNum], T0.[CardCode], T0.[CardName], T1.[ItemCode], T1.[Dscription], T1.[Quantity], T2.[TreeType] FROM ORDR T0  INNER JOIN RDR1 T1 ON T0.DocEntry = T1.DocEntry INNER JOIN OITM T2 ON T1.ItemCode = T2.ItemCode WHERE T0.[DocNum] = [%0] AND T2.[TreeType] = (N'P')
This is what i have at the moment, this only goes down one level, i cant think how i might drill down to lower levels. Any ideas?
Thanks

Answer 1

It will be a tough query to build.
Check this for just adding one level:
SELECT T0.DocNum, T0.CardCode, T0.CardName, T1.ItemCode, T1.Dscription, T1.Quantity
FROM ORDR T0
INNER JOIN RDR1 T1 ON T0.DocEntry = T1.DocEntry
WHERE T0.DocNum = [%0\] AND T1.ItemCode IN (SELECT Code From OITT)
UNION ALL
SELECT T0.DocNum, T0.CardCode, T0.CardName, T3.Code, T4.ItemName, T1.Quantity*T3.Quantity
FROM ORDR T0
INNER JOIN RDR1 T1 ON T0.DocEntry = T1.DocEntry
INNER JOIN OITT T2 ON T1.ItemCode = T2.Code
INNER JOIN ITT1 T3 ON T2.Code = T3.Father AND T3.Code IN (SELECT CODE FROM OITT)
INNER JOIN OITM T4 ON T3.Code = T4.ItemCode
WHERE T0.DocNum = [%0\]
Thanks,
Gordon