Query of concatenation on Access [duplicate] - ms-access

Question

Any help that can be provided to a Access and VB noob would be greatly appreciated. What I'm trying to do is concatenate the values from one table and insert it as a comma delimited value into a field in another table. I'm trying to take all the server names that are say Linux boxes and concatenate them into a different field.
Table A looks like this
Machine Name | Zone | Operating System
----------------------------------------
Server01 Zone A Linux
Server02 Zone B Linux
Server03 Zone A Windows
Server04 Zone C Windows
Server05 Zone B Solaris
Table B has the field I want to insert into: Affected_Machine_Names.
Now, I've tried looking through the Concatenate/Coalesce posts, but the SQL view in Access doesn't like the Declare statements. My VB skills suck badly and I can't seem to get the code to work in VB for Applications. Unfortunately, I can't get this database converted into our SQL farm cause I don't have a server available at the moment to host it.
Can anyone point me in the right direction?

Answer 1

You can use Concatenate values from related records by Allen Browne for this. Copy the function code from that web page and paste it into a new standard module. Save the module and give the module a name different from the function name; modConcatRelated would work.
Then I think you should be able to use the function in a query even though you're not proficient with VBA.
First notice I changed the field names in TableA to replace spaces with underscores. With that change, this query ...
SELECT
sub.Operating_System,
ConcatRelated("Machine_Name", "TableA",
"Operating_System = '" & sub.Operating_System & "'") AS Machines
FROM [SELECT DISTINCT Operating_System FROM TableA]. AS sub;
... produces this result set:
Operating_System Machines
Linux Server01, Server02
Solaris Server05
Windows Server03, Server04
If you can't rename the fields as I did, use a separate query to select the distinct operating systems.
SELECT DISTINCT TableA.[Operating System]
FROM TableA;
Save that as qryDistinctOperatingSystems, then use it in this version of the main query:
SELECT
sub.[Operating System],
ConcatRelated("[Machine Name]", "TableA",
"[Operating System] = '" & sub.[Operating System] & "'") AS Machines
FROM qryDistinctOperatingSystems AS sub;

Answer 2

This is a fairly basic VBA function that will loop through every row in a column, and concatenate it to a comma-delimited result string. i.e., for your example, it will return "Server01, Server02, Server03, Server04, Server05". (Don't forget to replace the column and table names)
Function ConcatColumn(OS As String) As String
Dim rst As DAO.Recordset
Set rst = CurrentDb.OpenRecordset("Select * from TableA")
Dim result As String
'For every row after the first, add a comma and the field value:
While rst.EOF = False
If rst.Fields("Operating System") = OS Then _
result = result & ", " & rst.Fields("MyValue")
rst.MoveNext
Wend
'Clean it up a little and put out the result
If Left(result, 2) = ", " Then result = Right(result, Len(result) - 2)
Debug.Print result
ConcatColumn = result
End Function
To use this,
1. ConcatColumn("Windows") will return "Server04, Server03"
2. ConcatColumn("Linux") will return "Server01, Server02"
3. ConcatColumn("Solaris") will return "Server05"
4. ConcatColumn("") will return "".