Return only duplicate values in Access SQL - sql

Question

I am having trouble trying to return only duplicate values in a query on Microsoft Access.
Here is my initial query:
SELECT tbl_dbextract_GP.GPNo,
[tbl_dbextract_GP].[GPFirst]+" "+[tbl_dbextract_GP].[GPLast] AS GPName,
Sum(tbl_main_ListLog.count_ToImport) AS ImportCount,
tbl_main_ListLog.SearchSequence
FROM ((tbl_main_ListLog
INNER JOIN tbl_dbextract_GPPractice
ON tbl_main_ListLog.GPPracticeID = tbl_dbextract_GPPractice.Id)
INNER JOIN tbl_dbextract_GP
ON tbl_dbextract_GPPractice.GPId = tbl_dbextract_GP.Id)
WHERE tbl_dbextract_GP.GPNo <> 'G0000'
GROUP BY tbl_dbextract_GP.GPNo,
[tbl_dbextract_GP].[GPFirst]+" "+[tbl_dbextract_GP].[GPLast],
tbl_main_ListLog.SearchSequence;
I only want to return results where there is at least 2 entries per GPNo.
The search sequence is incremental, so basically I am trying to find entries where there has been at least 2 searches.
This was my attempt:
SELECT
tbl_dbextract_GP.GPNo,
[tbl_dbextract_GP].[GPFirst] + " " + [tbl_dbextract_GP].[GPLast] AS GPName,
Sum(tbl_main_ListLog.count_ToImport) AS ImportCount,
tbl_main_ListLog.SearchSequence
FROM (((tbl_main_ListLog
INNER JOIN tbl_dbextract_GPPractice
ON tbl_main_ListLog.GPPracticeID = tbl_dbextract_GPPractice.Id)
INNER JOIN tbl_dbextract_GP
ON tbl_dbextract_GPPractice.GPId = tbl_dbextract_GP.Id)
LEFT JOIN (
SELECT tbl_main_ListLog.GPPracticeID as GPPID,
SUM(tbl_main_ListLog.SearchSequence) as SumSS
FROM tbl_main_ListLog
WHERE SumSS > 1
GROUP BY tbl_main_ListLog.GPPracticeID) SubQ
ON tbl_main_ListLog.GPPracticeID = SubQ.GPPID)
WHERE tbl_dbextract_GP.GPNo <> 'G0000'
GROUP BY tbl_dbextract_GP.GPNo,
[tbl_dbextract_GP].[GPFirst]+" "+[tbl_dbextract_GP].[GPLast],
tbl_main_ListLog.SearchSequence;
This didn't work, as it prompted me to manually enter the value for SumSS on execute, and that didn't return the right results anyway.
This is a sample output (Names redacted) - I want to return results where there is at least 2 entries per GPNo
EDIT: Modified attempt using Tim's solution - returning "Syntax error in JOIN operation":
SELECT
t3.GPNo,
t3.GPFirst + " " + t3.GPLast AS GPName,
SUM(t1.count_ToImport) AS ImportCount,
t1.SearchSequence
FROM (((tbl_main_ListLog t1
INNER JOIN tbl_dbextract_GPPractice t2
ON t1.GPPracticeID = t2.Id)
INNER JOIN tbl_dbextract_GP t3
ON t2.GPId = t3.Id)
INNER JOIN
(
SELECT t3.GPNo
FROM ((tbl_main_ListLog t1
INNER JOIN tbl_dbextract_GPPractice t2
ON t1.GPPracticeID = t2.Id)
INNER JOIN tbl_dbextract_GP t3
ON t2.GPId = g3.Id)
GROUP BY t3.GPNo
HAVING COUNT(*) > 1
) t4
ON t3.GPNo = t4.GPNo)
WHERE
t3.GPNo <> 'G0000'
GROUP BY
t3.GPNo,
t3.GPFirst + " " + t3.GPLast,
t1.SearchSequence;

Answer 1

Given that this is MS Access, which does not support analytic functions, doing a join to another subquery to impose the restriction on the number of searches seems like a reasonable approach, and your second attempt does not look far off. But you should be using the HAVING operator instead of WHERE, with a few other changes:
SELECT
t3.GPNo,
t3.GPFirst + " " + t3.GPLast AS GPName,
SUM(t1.count_ToImport) AS ImportCount,
t1.SearchSequence
FROM tbl_main_ListLog t1
INNER JOIN tbl_dbextract_GPPractice t2
ON t1.GPPracticeID = t2.Id
INNER JOIN tbl_dbextract_GP t3
ON t2.GPId = t3.Id
INNER JOIN
(
SELECT t3.GPNo
FROM tbl_main_ListLog t1
INNER JOIN tbl_dbextract_GPPractice t2
ON t1.GPPracticeID = t2.Id
INNER JOIN tbl_dbextract_GP t3
ON t2.GPId = t3.Id
GROUP BY t3.GPNo
HAVING COUNT(*) > 1
) t4
ON t3.GPNo = t4.GPNo
WHERE
t3.GPNo <> 'G0000'
GROUP BY
t3.GPNo,
t3.GPFirst + " " + t3.GPLast,
t1.SearchSequence;
In the subquery which I have aliased as t4, I do the same set of joins as your original query, but I then aggregate only by the GPNo. Also, I added a HAVING clause requiring that a GPNo appear two or more times in order to be retained in the result set. This subquery then filters off non matching GPNo records in your original query.

Answer 2

Add the Count(1) As Countr to your query and apply condition Countr>1 (apply HAVING clause as explained above).
Alternatively, in order to simplify your task, you can save the original working query as the intermediate one, e.g. Sub_With_Duplicates (Access has that feature), and then build another one (eg. Qry_No_Duplicates on the top of the intermediate and simply apply WHERE Countr>1 clause to that field. This should work.