SELECT DATE(tarih), COUNT(tarih) AS count
FROM siparisler where (tarih BETWEEN '2008-11-01' and '2008-12-31')
GROUP BY DATE(tarih)

DATE(tarih) count
2008-11-05 1
2008-11-06 1
2008-11-28 2
2008-12-04 2



count yerine sum daha iyi olabilir ...
SELECT DATE( tarih ) as tarih , sum( adet ) AS count
FROM siparisler
WHERE (
tarih
BETWEEN '2008-11-01'
AND '2008-12-31'
)
GROUP BY DATE(tarih)