SELECT DISTINCT count() in Microsoft Access - sql

Question

I've created a database where we can track bugs we have raised with our developers (Table: ApplixCalls) and track any correspondence related to the logged bugs (Table: Correspondence).
I'm trying to create a count where we can see the number of bugs which have no correspondence or only correspondence from us. This should give us the visibility to see where we should be chasing our developers for updates etc.
So far I have this SQL:
SELECT DISTINCT Count(ApplixCalls.OurRef) AS CountOfOurRef
FROM ApplixCalls LEFT JOIN Correspondence ON ApplixCalls.OurRef = Correspondence.OurRef
HAVING (((Correspondence.OurRef) Is Null)
AND ((ApplixCalls.Position)<>'Closed'))
OR ((ApplixCalls.Position)<>'Closed')
AND ((Correspondence.[SBSUpdate?])=True);
I'm finding that this part is counting every occasion we have sent an update, when I need it to count 1 where OurRef is unique and it only has updates from us:
OR ((ApplixCalls.Position)<>'Closed')
AND ((Correspondence.[SBSUpdate?])=True);
Hopefully that makes sense...
Is there a way around this?

Answer 1

MS Access does not support count(distinct). In your case, you can use a subquery. In addition, your query should not work. Perhaps this is what you intend:
SELECT COUNT(*)
FROM (SELECT ApplixCalls.OurRef
FROM ApplixCalls LEFT JOIN
Correspondence
ON ApplixCalls.OurRef = Correspondence.OurRef
WHERE (((orrespondence.OurRef Is Null) AND (ApplixCalls.Position) <> 'Closed')) OR
(ApplixCalls.Position <> 'Closed') AND (Correspondence.[SBSUpdate?] = True))
)
GROUP BY ApplixCalls.OurRef
) as x;
Modifications:
You have a HAVING clause with no GROUP BY. I think this should be a WHERE (although I am not 100% sure of the logic you intend).
The SELECT DISTINCT is replaced by SELECT . . . GROUP BY.
The COUNT(DISTINCT) is now COUNT(*) with a subquery.
EDIT:
Based on the description in your comments:
SELECT COUNT(*)
FROM (SELECT ApplixCalls.OurRef
FROM ApplixCalls LEFT JOIN
Correspondence
ON ApplixCalls.OurRef = Correspondence.OurRef
WHERE (((orrespondence.OurRef Is Null) AND (ApplixCalls.Position) <> 'Closed')) OR
(ApplixCalls.Position <> 'Closed') AND (Correspondence.[SBSUpdate?] = True))
)
GROUP BY ApplixCalls.OurRef
HAVING SUM(IIF(Correspondence.[SBSUpdate?] = False, 1, 0)) = 0
) as x;

Answer 2

I can not understand why are you using having clause. I hope this query will fullfill youe need.
SELECT DISTINCT Count(ApplixCalls.OurRef) AS CountOfOurRef
FROM ApplixCalls LEFT JOIN Correspondence ON ApplixCalls.OurRef = Correspondence.OurRef
HAVING (((Correspondence.OurRef) Is Null)
AND ((ApplixCalls.Position)<>'Closed'))
OR ((ApplixCalls.Position)<>'Closed')
AND ((Correspondence.[SBSUpdate?])=True);

Answer 3

If you are counting all the element that respond to you condition you don't need DISTINCT .. distinct if for removing duplicate result
SELECT Count(distinct ApplixCalls.OurRef) AS CountOfOurRef
FROM ApplixCalls LEFT JOIN Correspondence ON ApplixCalls.OurRef = Correspondence.OurRef
WHERE (((Correspondence.OurRef) Is Null)
AND ((ApplixCalls.Position)<>'Closed'))
OR ((ApplixCalls.Position)<>'Closed')
AND ((Correspondence.[SBSUpdate?])=True);