SQL 查询练习：成绩统计与分析

查询两门及两门以上不及格的学生姓名:\nSELECT name\nFROM scores\nGROUP BY name\nHAVING COUNT(*) >= 2 AND SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) >= 2; 2. 查询学生平均分:\nSELECT name, AVG(score) AS average_score\nFROM scores\nGROUP BY name; 3. 查询姓名是张三的学生成绩和:\nSELECT subject, score\nFROM scores\nWHERE name = '张三'; 4. 将学生信息按照分数倒序:\nSELECT \nFROM scores\nORDER BY score DESC; 5. 获取学生信息中分数最低的学生姓名和分数最高的学生姓名:\nSELECT name, score\nFROM scores\nWHERE score = (SELECT MIN(score) FROM scores)\n OR score = (SELECT MAX(score) FROM scores); 6. 查询两门及两门以上不及格同学的平均分:\nSELECT name, AVG(score) AS average_score\nFROM scores\nWHERE name IN (\n SELECT name\n FROM scores\n GROUP BY name\n HAVING COUNT() >= 2 AND SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) >= 2\n)\nGROUP BY name;