怎样确定有多少人登陆数据库

怎样确定有多少人登陆数据库

　　Sub ShowUserRosterMultipleUsers()

　　Dim cn As New ADODB.Connection

　　Dim cn2 As New ADODB.Connection

　　Dim rs As New ADODB.Recordset

　　Dim i, j As Long

　　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 Sub