为什么会显示“不允许约束调节说明”

Question

create table sc
(sno number(4),
cno number(4),
score number(4,1)
-- add constraints
constraints fk_sc_sno foreign key(sno)
references student(sno),
constraints ck_sc_score check(score>=0 and score<=100));

Answer 1

https://wenku.baidu.com/view/22a132b5c77da26925c5b074.html