custom aggregate function

I am trying to do the following:
in a select query I want to use Group by,and for one of the fields I want to be able to do a custom aggregate function (or call a function in a module) that concatenate the values of that field.

F1   F2    F3
A    v1    a
B    v2    b
B    v2    c

I want the result of the query using group by and the custom function to be (group by F1,F2):

F1     F2     F3(after applying the function)
A      V1      a
B      V2      b,c        ......  concatenate fields

in brief, I am trying to use a similar function to the Access aggregate functions (like sum) where I can use it with group by. Any help of outlining the code to do this and what values to pass to the function is appreciated.

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krzyczConnect With a Mentor Commented:
I have no idea.
I've just checked this function with one of my tables and it works fine.

Are you sure the function works? Did you try to compile all the modules?

Try to use this function in another simple query. i.e. just:

SELECT funcConcatenate("F3", "Table1", "F1='" & F1 & "' AND F2='" & F2 & "'",
",") AS F3
FROM Table1;

Maybe it will be easier to find an error.

Finally, you can send me a copy of your database (you can delete all the non-required objects). Just keep the table, the query and the module with the function. Then compress it and send me as a ZIP archive.
I'll try to help you.

Declare a public function (in any standard module):

Public Function funcConcatenate(txtFieldName As String, txtDomainName As String, txtCriteria As String, txtSeparator As String) As String
    Dim rs As DAO.Recordset
    Dim res As String
    res = ""
    Set rs = CurrentDb.OpenRecordset("SELECT " & txtFieldName & " FROM " & txtDomainName & " WHERE " & txtCriteria)
    If Not rs.BOF Then
        While Not rs.EOF
            res = res & rs(txtFieldName) & txtSeparator
        res = Left(res, Len(res) - Len(txtSeparator))
    End If
    funcConcatenate = res
End Function


SELECT F1, F2, funcConcatenate("F3", "TableName", "F1='" & F1 & "' AND F2='" & F2 & "'", ",") AS F3
FROM TableName

Need help? - Just @skme!
khalAuthor Commented:
it looks like this function will do it, but for some reason I am having an error when I am passing those variables from the query. It does not like the punctuation and it is giving error message
Compile error in query function funcConcatenate("F3", "Table1", "F1='" & F1 & "' AND F2='" & F2 & "'", ",") AS F3

do you see any problem with the punctuation?

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Try to use semicolons ";" instead of commas "," to separate parameters.

What is the way you open your query?
Is it a saved query?
khalAuthor Commented:
semicolons did not work. I use a saved select query. What is the difference?

khalAuthor Commented:
This is the exact SQL for the query

SELECT Table1.f1, Table1.f2, funcConcatenate("F3", "Table1", "F1='" & F1 & "' AND F2='" & F2 & "'", ",") AS F3
FROM Table1
GROUP BY Table1.f1, Table1.f2;

 and this is the error message:

compile error in query expression 'funcConcatenate("F3", "Table1", "F1='" & F1 & "' AND F2='" & F2 & "'", ",")'.
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