如何比较MS Access数据库中的日期？

Question

我的CheckTime输出格式为8/17/2014 5:45:22 PM。我如何比较CheckTime和Date()？

SELECT  c.Userid, c.CheckTime, 'Sign In' AS Action
FROM Checkinout c
WHERE c.CheckType = 'I' AND Format(CheckTime, "mm/dd/yyyy") = Date()
UNION
SELECT  c.Userid, c.CheckTime, 'Sign Out' AS Action
FROM Checkinout c
WHERE c.CheckType = 'O' AND c.CheckTime = Date();

Answer 1

我假设你也想记录结账吗？您打算如何将签到与相应的结账相匹配？

为什么不改变这样的表格呢？

 | UserId | CheckInTime | CheckOutTime |

然后你可以这样做：

SELECT c.Userid, c.CheckInTime, c.CheckOutTime,  
       IIF ( NOT ISNULL(c.CheckOutTime), 
             DateDiff("n",c.CheckTime,c.CheckTime)/60 & "." &          
             DateDiff("n",c.CheckTime,c.CheckTime) Mod 60,
             NULL) as TimeElapsed,
FROM Checkinout c;

注意：这会花费几小时和几分钟，但你可以做类似的事情来获取日期和时间。