题解 | #考试分数(四)#

SELECT job, 
ROUND((CASE WHEN COUNT(r) % 2=1 
		THEN (COUNT(r)/2)+0.5 ELSE (COUNT(r)/2 END),0) AS start, 
ROUND((CASE WHEN COUNT(r) % 2=1 
		THEN (COUNT(r)/2)+0.5 ELSE (COUNT(r)/2)+1 end),0) AS end 
FROM
	(SELECT job, RANK() OVER(PARTITION BY job ORDER BY score) r FROM grade
	 GROUP BY job, score) re
GROUP BY job
ORDER BY job