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2207/MySQL练习题/查询练习.md

@@ -311,10 +311,26 @@ HAVING GROUP_CONCAT(sc.course_id) = (
 );
 
 #10.查询没学过"张三"老师讲授的任一门课程的学生姓名
+SELECT s.`name`
+FROM students s
+WHERE s.id NOT IN (
+	SELECT st.id
+	FROM teachers t, courses c, students st, scores sc
+	WHERE t.id = c.teacher_id AND t.`name` = '张三' AND st.id = sc.student_id AND sc.course_id = c.id
+);
 
 #11.查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩
+SELECT sc.student_id, st.`name`,AVG(sc.score)
+FROM scores sc, students st
+WHERE sc.score < 60 AND sc.student_id = st.id
+GROUP BY sc.student_id
+HAVING COUNT(*) >= 2;
 
 #12.检索" 01 "课程分数小于 60，按分数降序排列的学生信息
+SELECT st.*
+FROM scores sc, students st
+WHERE sc.course_id = '01' AND sc.score < 60 AND sc.student_id = st.id
+ORDER BY sc.score DESC;
 
 #13.按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩