请问这个程序有错吗，关于外键的

Question

create table employee
(employee_name char(20),
street char(30),
city char(30),
primary key (employee_name))create table works
(employee_name char(20),
company_name char(15),
salary integer,
primary key (employee_name),
foreign key (employee_name) references employee,
foreign key (company_name) references company)create table company
(company_name char(15),
city char(30),
primary key (company_name))
create table manages
(employee_name char(20),
manager_name char(20),
primary key (employee_name),
foreign key (employee_name) references employee,
foreign key (manager_name) references employee)

Answer 1

foreign key (manager_name) references employee)
最后一句话外键里面有没有错

Answer 2

employee表里面并没有manager_name，主键是employee_name