where 条件里面 AVG函数报错！解决方法

create table t1( std_id number(4), student_name varchar2(50), subj1 number(3), subj2 number(3))SELECT subj1+subj2 total_marks, std_idFROM marksWHERE subj1 > AVG(subj1) AND subj2 > AVG(subj2)ORDER BY total_marks;