• ActiveX Data Objects (ADO), versions 2.0, 2.1 SP2, 2.5, 2.6

SYMPTOMS

The InfoMessage event of the connection object in ActiveX Data Objects (ADO) fires only when there is at least one Informational Message that resulted while establishing a connection to a database server. When opening an Asynchronous ADO connection, even if an InfoMessage event fires, no errors are appended to the Errors collection. In other words, the Errors collection is empty although there are one or more Info messages. If you open a synchronous connection, all Info Messages are appended to the Errors collection.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

ADO versions prior to 2.0 did not support events. Starting with ADO 2.0, Connection and Recordset objects have events associated with them. While establishing a connection to most database servers, the ODBC driver returns one or more Informational messages. These messages generally have a lower error severity level (usually below 10).

The following sample code establishes a connection to SQL Server Synchronously and Asynchronously using Visual Basic code. The Errors collection shows two Info Messages for Synchronous connection while it shows none for an Asynchronous connection.

Steps to Reproduce Behavior

1. Start standard project in Visual Basic 6.0.



2. Add a reference to the Microsoft ActiveX Data Objects 2.0 Library.



3. Add one command button to the default form.



4. Paste the following code in the form:




    
     Option Explicit

      Dim WithEvents Cn As ADODB.Connection

      Private Sub Cn_InfoMessage(ByVal pError As ADODB.Error, _
                                 adStatus As ADODB.EventStatusEnum, _
                                 ByVal pConnection As ADODB.Connection)

         If pConnection.Errors.Count > 0 Then
            For Each pError In pConnection.Errors
               MsgBox pError.Description
            Next
         Else
            MsgBox "The error collection is empty"
         End If

      End Sub

      Private Sub Command1_Click()

         Dim CnStr As String
         Dim i As Integer

         Set Cn = New ADODB.Connection

         CnStr = "Driver={SQL Server};Server=<ServerName>;" & _
                  "UID=<UserName>;PWD=<UserPassword>"

         Cn.Open CnStr   ', , , adAsyncConnect

         For i = 1 To 100
            DoEvents
         Next

         MsgBox "Connection is established"

      End Sub
 

5. Modify the connection string to match your server settings.



6. Run the project. Note that the informational messages display in a message box followed by a "Connection is established" message.



7. Uncomment the commented section of the Cn.Open line.



8. Run the project again and note that the following error occurs:




The error collection is empty.

With MDAC 2.5, the InfoMessage event may not be called when the collection is empty.

Additional query words:

Keywords : kbdta kbADO200 kbADO200bug kbADO210bug kbDatabase kbGrpVBDB kbGrpMDAC kbDSupport kbADO210sp2 kbMDAC250 kbADO250 kbMDAC260 kbADO260
Version : :2.0,2.1 SP2,2.5,2.6
Platform :
Issue type : kbprb
Technology :