sql - 我收到此错误 ORA-00907 : missing right parenthesis

Question

create table passenger(pnr number(10) primary key,
trainnumber number(5) foreign key references train(trainnumber),
noofseats number(4),
price number(4),
doj varchar2(10))

ORA-00907: 缺少右括号

Answer 1

foreign key表达式是多余的(读作:错误)。语法只是添加 references :

create table passenger(pnr number(10) primary key,
trainnumber number(5) references train(trainnumber), -- here
noofseats number(4),
price number(4),
doj varchar2(10))