Question

Hei guys, I’m trying to help my friend to design database tables. It is for a system tracking workers’ working hours in a factory by reading card info from certain card readers. Each time a worker log his in/out information, there would be an record saved.

My problem is, how can I calculate each worker’s working time (in minutes), each workday? A worker may work from 8:00AM~20:00PM, or 20:00PM~8:00AM.

Anyone can help me?

Thanks!

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You guys did give me a lot of help.
The previous design is a table with in-record or out-record. It was hard for me to locate which ones belong to the same work-time-span. I now use another table with records both have the in-time and out-time in the same record. Insert to save in-time, update to save out-time, which makes it easy to calculate the total minutes between in-time and out-time.

Answer 1

SELECT datediff(hh,'2011-08-30 04:47','2011-08-30 05:48') as [Hour(s) Worked]
Hour(s) Worked
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1