Concatenate rows into 1 - access 2007

Question

I\'m making a database in Access 2007, and currently I\'m struggling with a query. In only one column, it is possible to cose multiple answers. So, when I open the query I g

Answer 1

"Standard" SQL won't do this, I think. There may be some features in Access to return an array with column values... but unless someone else comes up with a cool suggestion based on such a capability, I'd say "no".

This kind of processing normally has to be done in the programming environment that called the SQL. Are you using some kind of report generator such as BIRT or are you doing "straight" JDBC? If the latter, then you can simply loop through your ResultSet to put that compound column together.

Answer 2

How about:

The code sample below will return a delimited list from either SQL or string input. This is how to use it in a query:

   SELECT documents.MembersOnly, 
       ConcatList("SELECT FName From Persons WHERE Member=True",":") AS Who, 
       ConcatList("",":","Mary","Joe","Pat?") AS Others
   FROM documents;

Or

   SELECT tc.Company, 
          ConcatList("SELECT Contract 
                      FROM tblservices 
                      WHERE CompanyKey=" & tc.[CompanyKey],", ") AS Contracts
   FROM tblCompanies tc

Sample Code

   Function ConcatList(strSQL As String, strDelim, _
            ParamArray NameList() As Variant)
   ''Reference: Microsoft DAO x.x Object Library
   Dim db As Database
   Dim rs As DAO.Recordset
   Dim strList As String

   Set db = CurrentDb

   If strSQL <> "" Then
       Set rs = db.OpenRecordset(strSQL)

       Do While Not rs.EOF
           strList = strList & strDelim & rs.Fields(0)
           rs.MoveNext
       Loop

       strList = Mid(strList, Len(strDelim) + 1)
   Else

       strList = Join(NameList, strDelim)
   End If

   ConcatList = strList

   End Function

From: http://wiki.lessthandot.com/index.php/Concatenate_a_List_into_a_Single_Field_%28Column%29

---

The link above now includes the ADO version below, which I include here as @onedaywhen never added a version.

This is faster and easier, but a lot more sensitive about field (column) names. You need to ensure that they are not reserved words. Another advantage of the ADO version is that you are not limited in the number of columns to be concatenated:

SELECT d.DeptID, d.Department, 
       ConcatADO("SELECT FName & ' ' & SName, Address FROM Persons 
                 WHERE DeptID=" & [d].[DeptID],", "," : ") AS Who
FROM Departments AS d INNER JOIN Persons AS p ON d.DeptID = p.DeptID
GROUP BY d.DeptID, d.Department, 3;

Function ConcatADO(strSQL As String, strColDelim, _
         strRowDelim, ParamArray NameList() As Variant)
Dim rs As New ADODB.Recordset
Dim strList As String

On Error GoTo Proc_Err

   If strSQL <> "" Then
       rs.Open strSQL, CurrentProject.Connection
       strList = rs.GetString(, , strColDelim, strRowDelim)
       strList = Mid(strList, 1, Len(strList) - Len(strRowDelim))
   Else
       strList = Join(NameList, strColDelim)
   End If

   ConcatADO = strList

Exit Function

Proc_Err:
    ConcatADO = "***" & UCase(Err.Description)
End Function