Create two tables, one for all of your employee data, and one to track
employee absences. Your primary key in the employee table would be something
like employee_id, and would be unique. This would also be the foreign key in
your employee absence table. Then, as employees are absent for whatever
reason, you would enter the absences and (and reasons) into the employee
absence table. You can then search and sort for absences by employee_id.