I am currently developing a QT C++ Application for my friend's shop. Simple application for inventory management and billing system. So, the DB will be in his computer itself which also hosts the application. There is only one system. So for DB I thought, I needed something light weight and I concluded I'll be using SQLite instead of MySQL which I use professionally.

Only today I found out that SQLite doesn't enforce type which was a bummer. That can be enabled either by writing constraints or during time of creation (CREATE query), I should append the word "STRICT" at the end. Note: I use DB Browser to view my SQLite DB.

So, my question is,

1. Is there any way to enable STRICT by default? Or ALTER the already created tables to add STRICT?
2. If not, what are the alternatives? I thought of MySQL and PostGreSQL. I prefer something light weight as in takes up the least amount of space for storage. Open for suggestions.
3. Despite this feature, should I stick with SQLite for my requirement in your opinion?

I would appreciate your answers. Thanks in advance.