MSQUERY: DDE Commands Available Only on System Channel

WORKAROUND

To avoid returning an error when you use one of the Microsoft Query DDE commands that is only supported on a system channel, use a system channel instead of a query channel in the DDE conversation. The following Visual Basic, Applications Edition, examples show how to establish a DDE conversation with Microsoft Query using either a system channel or a query channel.

System Channel

Sub UsingSystemChan()

Dim chan As Integer
Dim sql As String

   ' Establish DDE conversation using system channel
   chan = DDEInitiate("MSQUERY", "System")

   ' logon using NWind data source
   DDEExecute chan, "[Logon('NWind')]"

   ' Execute an SQL query to retrieve all records from Customer table
   DDEExecute chan, "[Open('SELECT Custmr_ID FROM Customer')]"

   'Return data to Sheet1 at cells A1:A63
   DDEExecute chan, "[Fetch('Excel', 'Sheet1', 'R1C1:R63C1', 'All')]"

   ' Close the DDE channel
   DDETerminate chan

End Sub
				

Query Channel

Sub UseQueryChannel()

Dim chan As Integer
Dim NRows, NCols

   ' Establish DDE conversation using query channel
   ' ** Note that QUERY1 must be open in Microsoft Query
   ' in order for the following command to work
   chan = DDEInitiate("MSQUERY", "query1")

   'Determine the number of rows and columns in query1
   NRows = DDERequest(chan, "NumRows")
   NCols = DDERequest(chan, "NumCols")

   ' Return the data in Query1 to Sheet1 starting at A1.
   ' ** The following two lines should be entered on one line.
   DDEExecute chan,"[Fetch('Excel', 'Sheet1', 'R1C1:R" & NRows(1) & "C"
    & NCols(1) & "', 'All')]"

   ' Close the DDE channel
   DDETerminate chan

End Sub
				

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