Grouping ignoring blank fields - sql

Question

I am having a hard time to identify (and fix) the grouping issue I have with the following query. My data has some Country fields blank and the query is ignoring them, only those with non blank values are converted to rows. I tried removing the country grouping but I get the error "You tried to execute a query that does not include the specified expression "Country" as part of an aggregate function". This is the query I have in Access:
TRANSFORM Count([passed courses].[Course Number])
SELECT [domain].[Account ID], [domain].[Account Name], [passed courses].[Learner Email Address], [passed courses].Category, [passed courses].Country, [passed courses].[Earliest Start_Date], [passed courses].[Latest End_Date]
FROM [Domain Master] AS [domain] INNER JOIN (SELECT d3.ID, d3.[Learner Email Address], d3.[Course Number], d3.[Transcript Status], d3.Domain, c2.Category, [passed levels].Country, [passed levels].[Earliest Start_Date], [passed levels].[Latest End_Date]
FROM
(SELECT [completed courses].[Learner Email Address], [completed courses].[Level], [completed courses].Category, [completed courses].[Completed Count], [completed courses].Country, [learner dates].[Earliest Start_Date], [learner dates].[Latest End_Date]
FROM
(SELECT [courses taken].[Learner Email Address], [courses taken].[Level], [courses taken].Category, Count([courses taken].ID) AS [Completed Count], [courses taken].Country
FROM
(SELECT d1.ID, d1.[Learner Email Address], d1.[Course Number], c1.[Level], c1.Category, d1.[Transcript Status], d1.Country
FROM [Data] AS d1
INNER JOIN [Courses] AS c1 ON d1.[Course Number] = c1.[Course Number]
)
AS [courses taken]
WHERE [courses taken].[Transcript Status] = "Completed"
GROUP BY [courses taken].[Learner Email Address], [courses taken].Level, [courses taken].Category, d1.Country
)
AS [completed courses]
INNER JOIN
(SELECT d2.[Learner Email Address], d2.Country, Min(d2.Start_Date) AS [Earliest Start_Date], Max(d2.End_Date) AS [Latest End_Date]
FROM [Data] AS d2
GROUP BY d2.[Learner Email Address], d2.Country
) AS [learner dates]
ON [completed courses].[Learner Email Address] = [learner dates].[Learner Email Address] AND
[completed courses].Country = [learner dates].Country
WHERE
([courses taken].Category = 'Sales') AND (
(([completed courses].Level = 1) AND ([completed courses].[Completed Count] >=5)) OR
(([completed courses].Level = 2) AND ([completed courses].[Completed Count] >=5)) OR
(([completed courses].Level = 3) AND ([completed courses].[Completed Count] >=1))
) OR
([courses taken].Category = 'Purchase') AND (
(([completed courses].Level = 1) AND ([completed courses].[Completed Count] >=5)) OR
(([completed courses].Level = 2) AND ([completed courses].[Completed Count] >=4)) OR
(([completed courses].Level = 3) AND ([completed courses].[Completed Count] >=1))
)
)
AS [passed levels]
INNER JOIN ([Data] AS d3 INNER JOIN Courses AS c2 ON ((d3.[Course Number] = c2.[Course Number])))
ON ([passed levels].Level = c2.Level) AND ([passed levels].[Learner Email Address] = d3.[Learner Email Address]) AND ([passed levels].Category = c2.Category)
) AS [passed courses] ON [domain].[Partner Domain] = [passed courses].Domain
GROUP BY [domain].[Account ID], [domain].[Account Name], [passed courses].[Learner Email Address], [passed courses].Category, [passed courses].Country, [passed courses].[Earliest Start_Date], [passed courses].[Latest End_Date]
PIVOT [passed courses].[Course Number];
Any help is appreciated!

Answer 1

What if you added a case statement into your query where if country = '' then return a unique GUID else return the Country column value and alias the case as Country
GUID function for access
You may need to wrap the whole query as a sub query to group by the Country aliased column though. This isn't tested, just a concept idea as I can't see any other way of grouping a country and ignoring blanks within the same select, or a less you did 2 selects and did a union instead.
Regards
Liam