- the 'ado' crate is the core library and does not contain any database driver
- the 'ado_postgresql' crate depends on 'ado' and is the PostgreSQL driver
- the 'ado_sqlite' crate depends on 'ado' and is the SQLite driver
There is missing the 'ado_mysql' crate because the library dependency
is tricky: we may need one of libmysqlclient or libmariadb libaries.