New to Java

Hello there, I really need help.


I'm trying to make this attendance tracking system so that when a user enters his or her ID the system wll remember his/her check in time. However I also need to find out either how late the person is or how early to store their over time and late.

So I get the time by using a timestamp, so I'm left with a timestamp that I store into the db. But the problem comes when trying to compute for the late or over time. To do that I have to get the normal login/checkin time from the employee schedules table in the db and either subtract that time from the checkInTime to compute for how late or subtract the checkIn time from it to find early.

The thing is, the schedule is stored in datetime format in the db since the db is sql. Also I have no idea on how to subtract the two dates via java. The month, date and year stored in the sql db are just fillers, all I need computed is the time difference of the hours and minutes between the checkInTime and the schedule.

I've tried to use datediff: SELECT e.employeeNumber, datediff('hh', startTime, checkInTime) as lateTime from employeeschedules e, timandattendance, contractualemployees c where c.scheduleNumber=e.scheduleNumber and t.employeeNumber=c.employeeNumber and t.checkInNumber=1;


But it keeps on giving out various errors: You have an error in your sql syntax check your manual that corresponds to your sql server version. for the right syntax to use near , checkInTime) as lateTime from employeeschedules e, timandattendance, contractualemployees c where c.scheduleNumber=e.scheduleNumber and t.employeeNumber=c.employeeNumber and t.checkInNumber=1;

My sql server is My SQL 5.0.5


Now I'm thinking of useing Gregorian instead, but I don't know how to use Gregorian and dont know the various methods. Can someone tell me what to do, provide some sample codes and references that I can use to accomplish what I need to do?