如何确定有多少人登陆数据库？

cn.Provider = "Microsoft.Jet.OLEDB.4.0"
cn.Open "Data Source=c:/Northwind.mdb"

cn2.Open "Provider=Microsoft.Jet.OLEDB.4.0;" _
& "Data Source=c:/Northwind.mdb"

' The user roster is exposed as a provider-specific schema rowset
' in the Jet 4 OLE DB provider. You have to use a GUID to
' reference the schema, as provider-specific schemas are not
' listed in ADO's type library for schema rowsets

Set rs = cn.OpenSchema(adSchemaProviderSpecific, _
, "{947bb102-5d43-11d1-bdbf-00c04fb92675}")

'Output the list of all users in the current database.

Debug.Print rs.Fields(0).Name, "", rs.Fields(1).Name, _
"", rs.Fields(2).Name, rs.Fields(3).Name

While Not rs.EOF
Debug.Print rs.Fields(0), rs.Fields(1), _
rs.Fields(2), rs.Fields(3)
rs.MoveNext
Wend

End SuD