How much is the salary of the employee who has the highest number of inspections done of all time?
the highest number of inspections done refers to max(count(employee_id))
SELECT T1.salary FROM employee AS T1 INNER JOIN ( SELECT employee_id, COUNT(inspection_id) FROM inspection GROUP BY employee_id ORDER BY COUNT(inspection_id) DESC LIMIT 1 ) AS T2 ON T1.employee_id = T2.employee_id