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SE WHEN IFNULL(sc.score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS "及格百分数"
FROM sc sc, course c
WHERE sc.cid = c.cid
GROUP BY sc.cid
ORDER BY AVG(sc.score) ASC,
100*SUM(CASE WHEN IFNULL(sc.score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
（14）查询所有学生的所有科目的成绩单（学号、姓名、语文、数学、英语、物理、平均分、总分（按照总分由高到低排序））
SELECT s.sid AS "学号", s.sname AS "姓名",
SUM(CASE c.cname WHEN "语文" THEN sc.score ELSE 0 END) AS "语文",
SUM(CASE c.cname WHEN "数学" THEN sc.score ELSE 0 END) AS "数学",
SUM(CASE c.cname WHEN "英语" THEN sc.score ELSE 0 END) AS "英语",
SUM(CASE c.cname WHEN "物理" THEN sc.score ELSE 0 END) AS "物理",
IFNULL(AVG(sc.score),0) AS "平均分",
IFNULL(SUM(sc.score),0) AS "总分"
FROM student s
LEFT OUTER JOIN sc sc ON s.sid=sc.sid
LEFT OUTER JOIN course c ON sc.cid=c.cid
GROUP BY s.sid, s.sname
ORDER BY IFNULL(SUM(sc.score),0) DESC
（15）查询总分排名在200-300（包含200和第300）之间的学生所有成绩单信息
SELECT s.sid AS "学号", s.sname AS "姓名",
SUM(CASE c.cname WHEN "语文" THEN sc.score ELSE 0 END) AS "语文",
SUM(CASE c.cname WHEN "数学" THEN sc.score ELSE 0 END) AS "数学",
SUM(CASE c.cname WHEN "英语" THEN sc.score ELSE 0 END) AS "英语",
SUM(CASE c.cname WHEN "物理" THEN sc.score ELSE 0 END) AS "物理",
IFNULL(AVG(sc.score),0) AS "平均分",
IFNULL(SUM(sc.score),0) AS "总分"
FROM student s
LEFT OUTER JOIN sc sc ON s.sid=sc.sid
LEFT OUTER JOIN course c ON sc.cid=c.cid
GROUP BY s.sid, s.sname
HAVING IFNULL(SUM(sc.score),0) BETWEEN 200 AND 300
ORDER BY IFNULL(SUM(sc.score),0) DESC
（16）查询总分排名在前四名的学生所有成绩单信息
SELECT s.sid AS "学号", s.sname AS "姓名",
SUM(CASE c.cname WHEN "语文" THEN sc.score ELSE 0 END) AS "语文",
SUM(CASE c.cname WHEN "数学" THEN sc.score ELSE 0 END) AS "数学",
SUM(CASE c.cname WHEN "英语" THEN sc.score ELSE 0 END) AS "英语",
SUM(CASE c.cname WHEN "物理" THEN sc.score ELSE 0 END) AS "物理",
IFNULL(AVG(sc.score),0) AS "平均分",
IFNULL(SUM(sc.score),0) AS "总分"
FROM student s
LEFT OUTER JOIN sc sc ON s.sid=sc.sid
LEFT OUTER JOIN course c ON sc.cid=c.cid
GROUP BY s.sid, s.sname
ORDER BY IFNULL(SUM(sc.score),0) DESC
LIMIT 0,4
（17）查询总分排名在前二名到四名的学生所有成绩单信息（limit 1,3表示从第二条数据开始，连续三条数据）
SELECT s.sid AS "学号", s.sname AS "姓名",
SUM(CASE c.cname WHEN "语文" THEN sc.score ELSE 0 END) AS "语文",
SUM(CASE c.cname WHEN "数学" THEN sc.score ELSE 0 END) AS "数学",
SUM(CASE c.cname WHEN "英语" THEN sc.score ELSE 0 END) AS "英语",
SUM(CASE c.cname WHEN "物理" THEN sc.score ELSE 0 END) AS "物理",
IFNULL(AVG(sc.score),0) AS "平均分",
IFNULL(SUM(sc.score),0) AS "总分"
FROM student s
LEFT OUTER JOIN sc sc ON s.sid=sc.sid
LEFT OUTER JOIN course c ON sc.cid=c.cid
GROUP BY s.sid, s.sname
ORDER BY IFNULL(SUM(sc.score),0) DESC
LIMIT 1,3
（18）查询学生平均成绩及其名次
(非本人)
SELECT 1+(SELECT COUNT( distinct 平均成绩)
FROM (
SELECT sid,AVG(score) AS 平均成绩
FROM sc
GROUP BY sid ) AS T1
WHERE 平均成绩 > T2.平均成绩) as 名次, S# as 学生学号,平均成绩
FROM (SELECT sid,AVG(score) 平均成绩
FROM sc GROUP BY sid ) AS T2
ORDER BY 平均成绩 desc
原文链接：htt
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