时间戳

首页 > 解决方案 > SQL 外键帮助。ORA-00907 缺少右括号

sql - SQL 外键帮助。ORA-00907 缺少右括号

问题描述

我是 SQL 新手，我在 CourseEnrollments 表中的外键方面遇到问题。

我不断收到错误报告 - ORA-00907：缺少右括号 00907。00000 -“缺少右括号 *原因：*操作：

看来所有逗号和括号都已到位。

Create Table Students 
(
StudentID INT NOT NULL,
Lastname VARCHAR2(25),
Firstname VARCHAR2(20),
Email VARCHAR2(40),
Enrollmentdate DATE,
CONSTRAINT student_pk PRIMARY KEY (StudentID)
);

/* This is the creation of the Students table */

Create Table Faculty 
(
FacultyID INT NOT NULL,
Lastname VARCHAR2(25),
Firstname VARCHAR2(20),
Email VARCHAR2(40),
Hiredate DATE,
CONSTRAINT faculty_pk PRIMARY KEY (FacultyID)
);

/* This is the creation of the Faculty table */

Create Table Courses 
(
CourseID INT NOT NULL,
"Subject (e.g. SDEV)" VARCHAR2(20),
"Catalognbr (e.g. 350)" NUMBER,
"Title (e.g. Database Security)" VARCHAR2(40),
CONSTRAINT course_pk PRIMARY KEY (CourseID)
);

/* This is the creation of the Courses table */

Create Table CourseEnrollments 
(
EnrollmentID INT NOT NULL,
  CONSTRAINT fk_Students
  FOREIGN KEY (StudentID)
  REFERENCES Students(StudentID)
CONSTRAINT fk_Faculty
  FOREIGN KEY (FacultyID)
  REFERENCES Faculty(FacultyID)
CONSTRAINT fk_Courses
  FOREIGN KEY (CourseID)
  REFERENCES Courses(CourseID)
CONSTRAINT enrollment_pk PRIMARY KEY (EnrollmentID)
);

标签： sqloracle

解决方案

首先，应首先明确定义需要约束的列，然后您可以定义约束。此外，当您定义多个约束时，它们需要用逗号分隔。这是工作代码（其余代码已经可以了）。

Create Table CourseEnrollments 
(
EnrollmentID INT NOT NULL,
StudentID int,
FacultyID int,
CourseID int,
CONSTRAINT fk_Students
  FOREIGN KEY (StudentID)
  REFERENCES Students(StudentID),
CONSTRAINT fk_Faculty
  FOREIGN KEY (FacultyID)
  REFERENCES Faculty(FacultyID),
CONSTRAINT fk_Courses
  FOREIGN KEY (CourseID)
  REFERENCES Courses(CourseID),
CONSTRAINT enrollment_pk PRIMARY KEY (EnrollmentID)
);

推荐阅读