Merge pull request #119 from leemamas/master

Update 关系型数据库MySQL.md

Day36-40/关系型数据库MySQL.md

@@ -401,7 +401,7 @@
    );
    
    -- 查询选了两门以上的课程的学生姓名(子查询/分组条件/集合运算)
-   select stuname from tb_student where stuid=(
+   select stuname from tb_student where stuid=any(
    	select stuid from tb_score group by stuid having count(stuid)>2
    )