Those are database related commands and belong in the data access layer.

>Ok I understand now:
>
>UI - communicates with business layer and users (Presentation)
>Business layer - it's middle layer, it's between UI and Data layer (Business Logic)
>Data Layer - it only communicates with Data Storage (DataBase)
>
>My question is:
>
>If I use CA (Up to now, I use CA with 3-Layered design and without ADO but with ODBC!) with ADODB and 3-Layered design (User Interface, Business Logic and Data Layer), in this case where is there (placed) ADODB commands like oConn.Open(),oConn.BeginTrans(),
>oRS.ActiveConnection = oConn, oRS.UpdateBatch(), oConn.RollbackTrans(), oRS.CancelBatch(), oConn.CommitTrans()... (which layer?)?
>In this case (with ADO commands) is unnecessary CA ?
>
>See you my preliminary mail for details and simple code for CA.Init().
>
>Best regards and thanks for help !
>Vojislav