This QVW app is for incremental load.
Which is set up in a way that rather than writing script for each table, you just have to fill in details for your tables in an inline table or through an excel file and few variables and you should be all set with the incremental load.
This is quite a basic document and handles just the cases where you are doing Insert/update load and does not handles delete scenarios and depending on your actual scenarios, you may need to modify it to suit your needs but hope this gives you a ground to start with.
While, I have tried to make it easy to understand but if you have some issues then let me know, also feel free to improve on it.
Hope it turns out to be helpful!