My query is returning duplicates - sql

Question

I have written an SQL query to filter for a number of conditions, and have used distinct to find only unique records.
Specifically, I need only for the AccountID field to be unique, there are multiple AddressClientIDs for each AccountID.
The query works but is however producing some duplicates.
Further caveats are:
There are multiple trans for each AccountID
There can be trans record both Y and N for an AccountID
I only want to return AccountIDs which have transaction for statuses other than what's specified, hence why I used not in, as I do not want the 2 statuses.
I would like to find only unique values for the AccountID column.
If anyone could help refine the query below, it would be much appreciated.
SELECT AFS_Account.AddressClientID
,afs_transunit.AccountID
,SUM(afs_transunit.Units)
FROM AFS_TransUnit
,AFS_Account
WHERE afs_transunit.AccountID IN (
-- Gets accounts which only have non post statuses
SELECT DISTINCT accountid
FROM afs_trans
WHERE accountid NOT IN (
SELECT accountid
FROM afs_trans
WHERE STATUS IN (
'POSTPEND'
,'POSTWAIT'
)
)
-- This gets the unique accountIDs which only have transactions with Y status,
-- and removes any which have both Y and N.
AND AccountID IN (
SELECT DISTINCT accountid
FROM afs_trans
WHERE IsAllocated = 'Y'
AND accountid NOT IN (
SELECT DISTINCT AccountID
FROM afs_trans
WHERE IsAllocated = 'N'
)
)
)
AND AFS_TransUnit.AccountID = AFS_Account.AccountID
GROUP BY afs_transunit.AccountID
,AFS_Account.AddressClientID
HAVING SUM(afs_transunit.Units) > 100
Thanks.

Answer 1

Since you confirmed that you have one-to-many relationship across two tables on AccountID column, you could use Max value of your AccountID to get distinct values:
SELECT afa.AddressClientID
,MAX(aft.AccountID)
,SUM(aft.Units)
FROM AFS_TransUnit aft
INNER JOIN AFS_Account afa ON aft.AccountID = afa.AccountID
GROUP BY afa.AddressClientID
HAVING SUM(aft.Units) > 100
AND MAX(aft.AccountID) IN (
-- Gets accounts which only have non post statuses
-- This gets the unique accountIDs which only have transactions with Y status,
-- and removes any which have both Y and N.
SELECT DISTINCT accountid
FROM afs_trans a
WHERE [STATUS] NOT IN ('POSTPEND','POSTWAIT')
AND a.accountid IN (
SELECT t.accountid
FROM (
SELECT accountid
,max(isallocated) AS maxvalue
,min(isallocated) AS minvalue
FROM afs_trans
GROUP BY accountid
) t
WHERE t.maxvalue = 'Y'
AND t.minvalue = 'Y'
)
)

Answer 2

SELECT AFS_Account.AddressClientID
,afs_transunit.AccountID
,SUM(afs_transunit.Units)
FROM AFS_TransUnit
INNER JOIN AFS_Account ON AFS_TransUnit.AccountID = AFS_Account.AccountID
INNER JOIN afs_trans ON afs_trans.acccountid = afs_transunit.accountid
WHERE afs_trans.STATUS NOT IN ('POSTPEND','POSTWAIT')
-- AND afs_trans.isallocated = 'Y'
GROUP BY afs_transunit.AccountID
,AFS_Account.AddressClientID
HAVING SUM(afs_transunit.Units) > 100
and max(afs_trans.isallocated) = 'Y'
and min(afs_trans.isallocated) = 'Y'
Modified your query with ANSI SQL join syntax. As you are joining the tables, you just need to specify the conditions without using the sub-queries you have.