如果日期在24小时内，从早上开始，到晚上结束，应该添加如下内容:

declare @Approval_date datetime
set @Approval_date =getdate()
Approval_date between @Approval_date +' 00:00:00.000' and @Approval_date +' 23:59:59.999'

你应该把这两个日期放在单引号之间，比如..

select Date, TotalAllowance from Calculation where EmployeeId = 1
             and Date between '2011/02/25' and '2011/02/27'

或者可以使用

select Date, TotalAllowance from Calculation where EmployeeId = 1
             and Date >= '2011/02/25' and Date <= '2011/02/27'

请记住，第一次约会包含所有内容，但第二次约会就不包含所有内容，因为它实际上是“2011/02/27 00:00:00”。

我喜欢使用1 MonthName 2015语法来表示日期:

   WHERE aa.AuditDate>='1 September 2015'
     AND aa.AuditDate<='30 September 2015'

对日期

对当前日期和前三天之间的选择日期的最佳查询:

  select Date,TotalAllowance from Calculation where EmployeeId=1 and Date BETWEEN       
DATE_SUB(CURDATE(), INTERVAL 3 DAY)  AND CURDATE() 

当前日期和未来三天之间的选择日期的最佳查询:

  select Date,TotalAllowance from Calculation where EmployeeId=1 and Date BETWEEN   
   CURDATE()  AND DATE_ADD(CURDATE(), INTERVAL 3 DAY)   

select Date,TotalAllowance 
from Calculation 
where EmployeeId=1
  and convert(varchar(10),Date,111) between '2011/02/25' and '2011/02/27'

SELECT Date, TotalAllowance  
FROM Calculation  
WHERE EmployeeId = 1 
  AND Date BETWEEN to_date('2011/02/25','yyyy-mm-dd') 
               AND to_date ('2011/02/27','yyyy-mm-dd');