Date Volume
Friday, July 01, 2011 31,400
Monday, July 04, 2011 50,600
Tuesday, July 05, 2011 60,600
Wednesday, July 06, 2011 50,200
Thursday, July 07, 2011 56,000
Friday, July 08, 2011 23,800
Monday, July 11, 2011 25,600
Tuesday, July 12, 2011 24,800
Wednesday, July 13, 2011 36,200
Thursday, July 14, 2011 22,800
Friday, July 15, 2011 62,800
Monday, July 18, 2011 47,000
Tuesday, July 19, 2011 75,800
Wednesday, July 20, 2011 66,600
Thursday, July 21, 2011 54,000
Friday, July 22, 2011 57,800
Monday, July 25, 2011 24,000
Tuesday, July 26, 2011 24,800
Wednesday, July 27, 2011 50,400
Thursday, July 28, 2011 52,800
Friday, July 29, 2011 34,000
Monday, August 01, 2011 28,600
Tuesday, August 02, 2011 12,400
Wednesday, August 03, 2011 39,200
Thursday, August 04, 2011 42,200
Friday, August 05, 2011 92,800
Monday, August 08, 2011 88,800
Tuesday, August 09, 2011 59,600
Wednesday, August 10, 2011 58,800
Thursday, August 11, 2011 50,000
Friday, August 12, 2011 39,800
Monday, August 15, 2011 15,800
Tuesday, August 16, 2011 22,800
Wednesday, August 17, 2011 37,000
Thursday, August 18, 2011 35,400
Friday, August 19, 2011 33,600
Monday, August 22, 2011 27,600
Tuesday, August 23, 2011 17,714
Wednesday, August 24, 2011 31,497
Thursday, August 25, 2011 38,800
Friday, August 26, 2011 12,310
Monday, August 29, 2011 33,200
Tuesday, August 30, 2011 47,600
我需要知道每个月的平均交易量
尝试以下查询：
SELECT
MONTH(Date) as Month,
AVG(Volume) as Volume
FROM
table
GROUP BY
MONTH(Date)