SELECT date_due_for_return, users_user_id, date_issued, date_returned
FROM Books_out_on_loan
INNER JOIN users ON users.user_id = Books_out_on_loan.Users_user_id
WHERE data_issued +10 < curdate() AND date_returned is null;
data_issued + 10 < curdate()
`date_issued` < CURDATE() - INTERVAL 10 DAY