DISTINCT is not working - sql

Question

SQL query in Ms-Access
INSERT INTO tblTmpEventLog( TrackingNumber, PartNumber, PartNumberChgLvl,
EnteredBy, EventTypeSelected, EventDate )
SELECT DISTINCT tblRevRelLog_Detail.RevRelTrackingNumber,
tblRevRelLog_Detail.PartNumber, tblRevRelLog_Detail.ChangeLevel,
[Forms]![frmEventLog_Input]![EnteredBy] AS EnteredBy,
[Forms]![frmEventLog_Input]![EventTypeSelected] AS EventTypeSelected,
CDate([Forms]![frmEventLog_Input]![EventDate]) AS EventDate
FROM tblRevRelLog_Detail LEFT JOIN tblEventLog
ON (tblEventLog.PartNumber = tblRevRelLog_Detail.PartNumber)
AND (tblEventLog.PartNumberChgLvl = tblRevRelLog_Detail.ChangeLevel)
WHERE ((([tblRevRelLog_Detail]![RevRelTrackingNumber]) =
[Forms]![frmEventLog_Input]![TrackingNumber]))
AND ((tblEventLog.PartNumber) NOT IN
(SELECT tblEventLog.PartNumber FROM tblEventLog
WHERE tblEventLog.EventTypeSelected = 'pn REMOVED From Wrapper'
AND tblEventLog.TrackingNumber =
tblRevRelLog_Detail.RevRelTrackingNumber
AND tblEventLog.PartNumber = tblRevRelLog_Detail.PartNumber
AND tblEventLog.PartNumberChgLvl =
tblRevRelLog_Detail.ChangeLevel
));
DISTINCT keyword for EnteredBy, EventTypeSelected is not working..I mean, data for these columns is not displaying when I use DISTINCT keyword.
EVENTDATE is working fine, but I do not understand why is it not displaying for EneteredBy and EventTypeSelected columns.
Can anyone tell me how to handle this?

Answer 1

It may be that the query can't interpret properly from the form directly as the final data type. However in your date field, you are wrapping it in a function CDATE( ... ). So, the SQL engine knows the result type. I would suggest doing the same for the other fields. Ex: doing a CAST ( ...your form control... as DateTime ) as OtherColumn, etc... I THINK Access allows casting, but not positive. Otherwise, pre-pull the form value into a declared data type variable and use THAT variable in the query AS OtherColumn as you are doing.
Additionally to what #Jack mentioned, you can always go back to your account, look at your historical question, and click on whatever answers actually helped / solve your problems. Some questions never do get answers and that's ok, just give credit to those that DO help.

Answer 2

I have found in the past (I don't remember which old version of Access this was) that if you set the value of a form control in VBA, and then use that control in a query, the query will not see the value you set in VBA. If the user edits the control normally, the query sees the expected value. Perhaps that's what happened here.
To work around that, you can declare a VBA function that returns the desired value. For example, instead of this:
SELECT ..., Forms!MainForm!TextEntry AS TextEntry, ... FROM ...
use this:
SELECT ..., GetTextEntry() AS TextEntry, ... FROM ...
along with this:
Public Function TextEntry() As Variant
TextEntry = Forms!MainForm!TextEntry
End Function