"sql": "SELECT subject, ROUND(AVG(score), 2) AS avg_score FROM student_scores GROUP BY subject ORDER BY avg_score DESC;"
},
{
"title": "统计各科目及格率",
"sql": "SELECT subject, ROUND(COUNT(CASE WHEN score >= 60 THEN 1 END) * 100.0 / COUNT(*), 2) as pass_rate FROM student_scores GROUP BY subject ORDER BY pass_rate DESC;"
},
{
"title": "统计各科目成绩分布",
"sql": "SELECT subject, COUNT(CASE WHEN score >= 90 THEN 1 END) as excellent, COUNT(CASE WHEN score >= 75 AND score < 90 THEN 1 END) as good, COUNT(CASE WHEN score >= 60 AND score < 75 THEN 1 END) as pass, COUNT(CASE WHEN score < 60 THEN 1 END) as fail FROM student_scores GROUP BY subject;"