一组按日期显示的价格数据,放在表price中,如:
Date1 price
2007-7-31 ¥30.00
2007-8-1 ¥30.00
2007-8-2 ¥30.00
2007-8-4 ¥30.00
2007-8-5 ¥30.00
2007-8-6 ¥30.00
2007-8-7 ¥29.00
2007-8-8 ¥30.00
2007-8-9 ¥31.00
2007-8-18 ¥38.00
2007-8-19 ¥38.00
2007-8-20 ¥38.30
2007-8-21 ¥38.50
2007-8-22 ¥38.50
2007-8-23 ¥40.50
2007-8-24 ¥39.50
2007-8-25 ¥41.00
2007-8-26 ¥39.50
2007-8-27 ¥39.50
2007-8-28 ¥39.60如果按周(以中国习惯)显示每周最先一天的价格、最后一天的价格、每周最高价、最低价?