I remember reading somewhere that SQLite follows the standard completely, when possible (as in, switching databases, etc. is not implemented, as well as using dynamic types). One would expect that the other flavors would also follow the standard, and then tack on some extra features.
Are these expectations correct? If so, I would expect that (almost) any valid SQLite code would also be valid PostgreSQL, MySQL, or other SQL flavors as well.
Is this true? Or,
TL;Dr is there any valid SQLite that doesn't use its file-based nature, that isn't valid in other dialects?