Select and calculate hours with varchar datatype

0

Hello, by date, I need to make the longest hour minus the smallest hour of X people.

1 How do I select the largest and smallest by a date? I've tried a lot, I can post here the attempts.

2 The data is written as varchar, how do you find the difference between hours / minutes? I've already tried a lot, I can post.

Thank you in advance.

DataAcesso	HoraAcesso
20150401	81822
20150401	81855
20150401	102835
20150401	105401
20150401	123939
20150401	125526
20150401	152418
20150401	152522
20150401	162554
20150401	162752
20150401	180024
    
asked by anonymous 11.06.2015 / 15:31

0 answers