Public cn As ADODB.Connection
Public rs As ADODB.Record

Public Sub Conectar()
  Set cn = New ADODB.Connection
  Set rs = New ADODB.Recordset
  rs.CursorLocation = adUseClient
'  cn.Open "Driver={MySQL ODBC 3.51 Driver};Server=localhost;Database=gestvehicular;User=root;Password=123456;Option=3;"
  cn.Open "Provider=SQLNCLI10;Server=.;Database=Northwind;Trusted_Connection=yes;"
End Sub

Public Sub Desconectar()
  On Local Error Resume Next
  rs.Close
  Set rs = Nothing
  cn.Close
  Set cn = Nothing
End Sub

Public Function Existe(id As Integer) As Boolean


On Error GoTo tratarError
  Dim cmd As New Command
  Conectar
  With cmd
    .ActiveConnection = cn
    .CommandText = "SELECT COUNT(*) FROM Employees WHERE EmployeeID=@id"
    .CommandType = adCmdText
    .NamedParameters = True
    .Parameters.Append .CreateParameter("@id", adInteger, adParamInput, , id)
    .Execute
    If (rs.EOF) Then

  End With
  On Error GoTo 0
  Desconectar
  Exit Function
tratarError:
  MsgBox Err.Description
End Function