Three tire architecture for database application ?

[Lykurg]

2- For database application, its better to use Qt's MV architecture (e.g: QSqlTableModel and QTableView) or to use 3-tire architecture (Build the layers and use SQL statement)? from the point of application design,developing time and ease of modification.

Well you can do the work by your own, but I would go the easy why and use what Qt provides you (QtSql Module). Because with that you can be sure, that it fit all other Qt classes and many people have developed and tested it. And I doubt that you can gain much speed if you program custom layers.