请熟练的写出下列T-sql语句。求计算机系每个学生的选课门数列出学号选课门数和选课情况其中选课情况=3为多1-2门为一般少于1门的少 请操作

SELECT s.stu_id AS 学号, COUNT() AS 选课门数, CASE WHEN COUNT() >= 3 THEN '多' WHEN COUNT() >= 1 AND COUNT() <= 2 THEN '一般' ELSE '少' END AS 选课情况 FROM student s JOIN score sc ON s.stu_id = sc.stu_id JOIN course c ON sc.course_id = c.course_id WHERE s.dept = '计算机系' GROUP BY s.stu_id;