MySQL Simple Solution
select \n    event_day as day,emp_id,sum(out_time-in_time) as total_time\nfrom\n    Employees\ngroup by event_day,emp_id;\n
select \n    event_day as day,emp_id,sum(out_time-in_time) as total_time\nfrom\n    Employees\ngroup by event_day,emp_id;\n
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