let mut stmt = connection.prepare("SELECT chat_id FROM users GROUP BY chat_id ORDER BY chat_id ASC").unwrap();
        let chats_iter = stmt.query_map(&[], |row| {
            row.get(0)
        }).unwrap();

        for chat in chats_iter
        {
            chats.push(chat.unwrap());
        }

thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: InvalidColumnType(0, Integer)', C:\Users\golod\.cargo\registry\src\github.com-1ecc6299db9ec823\rusqlite-0.14.0\src\row.rs:149:31
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: InvalidColumnType(1, Integer)', C:\Users\golod\.cargo\registry\src\github.com-1ecc6299db9ec823\rusqlite-0.14.0\src\row.rs:149:31