关于按日期查询

当在保存数据到表中时日期格式后面带了时间　当在查询时就查询不到当天的数据了　在这里我分成三种情况讲述：

1. 当带时间的情况下　只按一个日期查　'select * from v_sale_head where out_date BETWEEN '''+datetostr(DateTimePicker1.Date)+' 00:00:00'' AND '''+datetostr(DateTimePicker1.Date)+' 23:59:59'''; 
2. 两个日期的　'select * from v_sale_detail where out_date>='+QuotedStr(FormatDateTime('yyyy-mm-dd',IncDay(DateTimePicker2.Date, -1)))+' AND out_date<='+QuotedStr(FormatDateTime('yyyy-mm-dd',IncDay(DateTimePicker3.Date, 1)));
3. 当保存数据不带时间的　'select * from v_inhouse_find  where 入库日期>='''+FormatDateTime('yyyy-mm-dd',DateTimePicker1.Date)+'''and 入库日期<='''+FormatDateTime('yyyy-mm-dd',DateTimePicker2.Date)+'''';