datetime类型的时间条件怎么设置

select start_time from a
start_time
'2011-03-09 09:21:27.740000'
'2011-03-09 09:21:24.801000'
'2011-03-09 09:21:23.784000'
'2011-03-09 09:21:26.810000'
'2011-03-09 09:21:26.789000'
'2011-03-09 09:21:24.821000'
'2011-03-09 09:21:27.839000'
'2011-03-09 09:21:25.727000'
'2011-03-09 09:21:25.706000'
'2011-03-09 09:21:24.831000'
'2011-03-09 09:21:22.716000'
'2011-03-09 09:21:25.673000'
'2011-03-09 09:21:26.867000'
'2011-03-09 09:21:26.762000'

我想查9:20--10:00的数据,where怎么写?

>=''2011-03-09 09:20' and <= ''2011-03-09 10:00''
注意datetime类型的精度是 1/300秒