Filtering duplicate participants from query based on a study name

[Puciral]

I have been working on a database that matches participant demographic
information to the studies they have participated in.
Each study and participant has unique autonumber IDs and I have combined
them both in a separate table with dates.
Participants have taken multiple studies and thus they show up multiple
times in a query.

Filtering out a study only cancels out the participants that have taken the
study and not all instances of the participant. I want to be able to take
the experiment name from a form such as
[Forms]![ExperimentFilter]![Expfilter] and then have that filter out all the
PartID associated with that StudyID.

Right now I have this in my query:
SELECT DISTINCT Hess_main_participant_table.Part_ID,
Hess_main_participant_table.Last, Hess_main_participant_table.First,
Dates_for_each_study_and_Participant.StudyID
FROM Dates_for_each_study_and_Participant INNER JOIN
Hess_main_participant_table ON Dates_for_each_study_and_Participant.Part_ID =
Hess_main_participant_table.Part_ID
GROUP BY Hess_main_participant_table.Part_ID,
Hess_main_participant_table.Last, Hess_main_participant_table.First,
Dates_for_each_study_and_Participant.StudyID
HAVING
(((Dates_for_each_study_and_Participant.StudyID)=[Forms]![ExperimentFilter]![Expfilter]))
ORDER BY Hess_main_participant_table.Last;

Right now the [Forms]![ExperimentFilter]![Expfilter] is giving me nothing
when I put it into the criterion and run the query even though I've triple
checked the spelling, etc.

I am a novice access user (3 months) and I've messed with the VB code a
little to make the msgboxs work and clean up some things but I was hoping I
could accomplish the filtering using queries and some kind of IIF and where
condition to take out all the PartID.

Thank you in advance for looking

 

[Puciral]

I'll quickly summarize the main point since I may have been too verbose:

I wish to be able to select a name of a study and find all the PartID #s
associated with that StudyID and then filter out all the PartID #s that are
returned.
A 1 to many filter that is based on a study name filter.

Even a basic syntax or code helping would be VERY grately appreciated.