ADOX 2.5

Connection Close Method, Table Type Property Example (VB)

Setting the ActiveConnection property to Nothing should "close" the catalog. Associated collections will be empty. Any objects that were created from schema objects in the catalog will be orphaned. Any properties on those objects that have been cached will still be available, but attempting to read properties that require a call to the provider will fail.

' BeginCloseConnectionVB
Sub Main()
    On Error GoTo CloseConnectionByNothingError
    
    Dim cnn As New ADODB.Connection
    Dim cat As New ADOX.Catalog
    Dim tbl As ADOX.Table

    cnn.Open "Provider='Microsoft.Jet.OLEDB.4.0';" & _
        "Data Source= 'c:\Program Files\Microsoft Office\" & _
        "Office\Samples\Northwind.mdb';"
    Set cat.ActiveConnection = cnn
    Set tbl = cat.Tables(0)
    Debug.Print tbl.Type    ' Cache tbl.Type info
    Set cat.ActiveConnection = Nothing
    Debug.Print tbl.Type    ' tbl is orphaned
    ' Previous line will succeed if this was cached
    Debug.Print tbl.Columns(0).DefinedSize
    ' Previous line will fail if this info has not been cached

    'Clean up
    cnn.Close
    Set cat = Nothing
    Set cnn = Nothing
    Exit Sub
    
CloseConnectionByNothingError:
    Set cat = Nothing
    
    If Not cnn Is Nothing Then
        If cnn.State = adStateOpen Then cnn.Close
    End If
    Set cnn = Nothing
    
    If Err <> 0 Then
        MsgBox Err.Source & "-->" & Err.Description, , "Error"
    End If
End Sub
' EndCloseConnectionVB

Closing a Connection object that was used to "open" the catalog should have the same effect as setting the ActiveConnection property to Nothing.

Sub CloseConnection()
    On Error GoTo CloseConnectionError
    
    Dim cnn As New ADODB.Connection
    Dim cat As New ADOX.Catalog
    Dim tbl As ADOX.Table
    
    cnn.Open "Provider='Microsoft.Jet.OLEDB.4.0';" & _
        "Data Source= 'c:\Program Files\Microsoft Office\" & _
        "Office\Samples\Northwind.mdb';"
    Set cat.ActiveConnection = cnn
    Set tbl = cat.Tables(0)
    Debug.Print tbl.Type    ' Cache tbl.Type info
    cnn.Close
    Debug.Print tbl.Type    ' tbl is orphaned
    ' Previous line will succeed if this was cached
    Debug.Print tbl.Columns(0).DefinedSize
    ' Previous line will fail if this info has not been cached

    'Clean up
    Set cat = Nothing
    Set cnn = Nothing
    Exit Sub
    
CloseConnectionError:

    Set cat = Nothing
    
    If Not cnn Is Nothing Then
        If cnn.State = adStateOpen Then cnn.Close
    End If
    Set cnn = Nothing

    If Err <> 0 Then
        MsgBox Err.Source & "-->" & Err.Description, , "Error"
    End If
End Sub
' EndCloseConnection2VB

See Also

ActiveConnection Property | Catalog Object | Column Object | Columns Collection | Table Object | Tables Collection | Type Property (Table)

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