Public Sub QueryFunction(ByVal p1 as Boolean, ByVal p2 as Boolean, ByVal p3 as String)
{
   Dim str as String
   str = " select * from T1 "
   If p1 Then
      str &= " join T2 on T2.id = T1.id"
   End If

   If p2 Then
      str &= " join T3 on T3.id = T1.id and T2.name = " & p3
   End If

   ExecuteQuery(str)

}