Doufám, že to pomůže
SELECT ID, weigth, created_on, WEEK(created_on) week
FROM weight
WHERE created_on BETWEEN start_date AND end_date
ORDER BY week
Doufám, že to pomůže
SELECT ID, weigth, created_on, WEEK(created_on) week
FROM weight
WHERE created_on BETWEEN start_date AND end_date
ORDER BY week