Jeg ville generere en række dage og slutte mig til din sæsontabel og bruge en enkelt forespørgsel for at få det ønskede resultat, f.eks.:
SELECT dates.Date,
coalesce(s.price, 0) AS price
FROM
(SELECT a.Date
FROM
( SELECT curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY AS Date, '0' AS price
FROM
(SELECT 0 AS a
UNION ALL SELECT 1
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 4
UNION ALL SELECT 5
UNION ALL SELECT 6
UNION ALL SELECT 7
UNION ALL SELECT 8
UNION ALL SELECT 9) AS a
CROSS JOIN
(SELECT 0 AS a
UNION ALL SELECT 1
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 4
UNION ALL SELECT 5
UNION ALL SELECT 6
UNION ALL SELECT 7
UNION ALL SELECT 8
UNION ALL SELECT 9) AS b
CROSS JOIN
(SELECT 0 AS a
UNION ALL SELECT 1
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 4
UNION ALL SELECT 5
UNION ALL SELECT 6
UNION ALL SELECT 7
UNION ALL SELECT 8
UNION ALL SELECT 9) AS c) a
WHERE a.Date BETWEEN '$from' AND '$to'
ORDER BY a.Date) dates
LEFT JOIN seasons s ON dates.Date BETWEEN s.start AND s.END
Den komplicerede indre forespørgsel undgår oprettelsen af en midlertidig tabel (taget fra generate dage fra datointerval ) og virker i op til 1000 dage, men det ville være fint at oprette en midlertidig tabel.