如果有一元关系，如何在表中插入信息

Question

create table Employee(
staff_id_employee int primary key ,
gender char(1) check (gender in('F','M')),
staff_id int foreign key REFERENCES Staff(staff_id),
manager_id int foreign key references Employee(staff_id_employee)
);

我该如何在这个表中插入信息这里的文字是一名员工管理其他员工。如果有人能给我举个例子，因为我不知道该写什么，而不是问号"？？？"。在这种情况下，WHat是manager_id的值

INSERT into Employee(staff_id_employee, gender, staff_id, manager_id) VALUES (30000,'F',6007,????)

Answer 1

如果需要查找经理的Id，则需要insert select

INSERT into Employee(staff_id_employee, gender, staff_id, manager_id) 
SELECT 30000,'F',6007, staff_id_employee
from Employee
where staff_id = [Manager's staff ID]

Answer 2

如果Employee 3000没有经理，通常会插入一个空

INSERT into Employee(staff_id_employee, gender, staff_id, manager_id) 
VALUES (30000,'F',6007, null)

否则，插入经理的ID。