日期查询优化问题

1：select * from Sale where  format(SJoinTime,'yyyy-MM-dd')>=#2011-07-03# and format(SJoinTime,'yyyy-MM-dd')<=#2011-08-03#

 

2：select * from Sale where SJoinTime>=#2011-07-03 00:00:00# and format(SJoinTime,'yyyy-MM-dd')<#2011-08-04 00:00:00#

 

第一条语句要对SJoinTime进行格式话，如果数据量大，就比较耗时