SQL LEFT JOIN not working in MS Access - sql

Question

The following SQL query returns no data for the LEFT JOIN in MS Access.
SELECT * FROM
(
SELECT Operation_Part.PPC,
Operation_Part.TargetOperationsPerHour as JPH,
Operation_Part.Misc1 as [JPh Alt 1],
STR(Operation_Part.SeqNr) as Sequence,
Operation_Part.idPart,
Operation_Part.idOperationPart,
Operation.OperationType as Operation,
tblOperationType.OperationType as [Operation Type]
FROM tblOperationType
RIGHT JOIN (Operation INNER JOIN Operation_Part ON Operation.idOperation = Operation_Part.idOperation)
ON tblOperationType.idOpType = Operation.OperationTID
WHERE Operation_Part.VsbLDq = 0
AND Operation_Part.idPart <> 0 AND Operation_Part.idPart = 1271)
AS [AA]
LEFT JOIN (SELECT Sum([Cptotal]) AS DownTime,
TransactionDetail.idPart,
STR(TransactionDetail.seq_number) as Sequence
FROM ([Transaction] INNER JOIN TransactionDetail ON [Transaction].idTransaction = TransactionDetail.idTransaction)
WHERE [Transaction].idTransactionType=29
AND TransactionDetail.WorkOrderNumber = 'PR23144'
GROUP BY TransactionDetail.idPart, STR(TransactionDetail.seq_number))
AS [EE]
ON AA.idPart = EE.idPart AND EE.Sequence=AA.Sequence
In SQL Server the query does return the downtime value of 1.08 as required (see pics below).
First select returns:
Second select returns:
MS Access result:
SQL server result:
How do I make it work in MS Access?

Answer 1

This is only a guess, but it may well have something to do with the nulls in the applicable columns of the rows you dont really want.
Suggest you change
SELECT Sum([Cptotal]) AS DownTime,
to
SELECT Sum(IIf(IsNull([CpTotal]), 0, [CpTotal])) AS DownTime
In Access I always use CStr(...) instead of Str(...)
Aside from this, painful though it may be, I'd suggest turning the left-joined component into a separate query, or if you dont use queries, building a temporary table with this data which is then left joined into the original query.