SELECT OBJECT_NAME,OBJECT_TYPE FROM USER_OBJECTS WHERE OBJECT_NAME='Teaching';也是没选中行,但新建就有错。
drop后有purge,desc也是“未选定行”,可就是建不了表
create table Teaching(tno number(6),
cno varchar2(6),
language varchar2(10) check(language in('Chinese','Bilingual','English')),
primary key(tno,cno),
foreign key(tno) references Teacher(tno),
foreign key(cno) references Course(cno));
è¿æ¯å®æ´ç