Sql 获取ORA-00904无效标识符错误，但已创建标识符

我在使用此代码时遇到问题：

CREATE TABLE Department (
  Department_ID INTEGER PRIMARY KEY NOT NULL,
  Department_Name CHAR(15) NOT NULL,
  Department_Location CHAR(13) NOT NULL,
  Department_Phone_Number INTEGER NOT NULL,
  CONSTRAINT fk_Employee
  FOREIGN KEY (Employee_ID)
  REFERENCES Employee(Employee_ID)
);

我收到一个

ORA-00904:“EMPLOYEE_ID”：无效标识符

错误，但我已经用以下代码创建了一个EMPLOYEE表：

CREATE TABLE Employee (
  Employee_ID INTEGER PRIMARY KEY NOT NULL,
  Employee_Name CHAR(25) NOT NULL,
  Date_Of_Birth DATE NOT NULL,
  Job_Title CHAR (15) NOT NULL,
  Marriage_Date DATE NULL,
  Spouse_Name CHAR(25) NULL
);

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知道我做错了什么吗？

您需要有Employee\u id列，在该列上您还可以在部门表中定义外键：

CREATE TABLE Department
(Department_ID integer PRIMARY KEY NOT NULL,
Department_Name CHAR(15) NOT NULL,
Department_Location CHAR(13) NOT NULL,
Department_Phone_Number integer NOT NULL,
Employee_ID integer null,
CONSTRAINT fk_Employee
FOREIGN KEY (Employee_ID)
REFERENCES Employee(Employee_ID));

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在某种程度上，我看到dedepartment表中没有EMPLOYEE_ID列。首先在department表中创建列，然后为employee表引用外键