计算加班工时并将加班更新到表

Question

I have table columns workhours and overtime, and I would like to do a SQL or PHP query that checks if the workinghours are over 8 hours and if so it UPDATEs the worked overtime to overtime column.

Here's my table:

id   workinghours    overtime
1,   4.79,           ---
2,   8.73,           ---
3,   7.97,           ---  

For example on the second row there is 8.73 hours of work and so it would update the 0.73 hours to the overtime column.

Answer 1

query :

update work set overtime= (case when working > 8 then (working - 8) else null end);

check SQL Fiddle Demo