mysql - 相互依赖的外键

MySQL：相互依赖的外键

sql
SET FOREIGN_KEY_CHECKS = 0;
-- 创建表1
CREATE TABLE table1 (
    id INT PRIMARY KEY,
    table2_id INT,
    FOREIGN KEY (table2_id) REFERENCES table2(id)
);
-- 创建表2
CREATE TABLE table2 (
    id INT PRIMARY KEY,
    table1_id INT,
    FOREIGN KEY (table1_id) REFERENCES table1(id)
);
SET FOREIGN_KEY_CHECKS = 1;

sql
SET FOREIGN_KEY_CHECKS = 1;

sql
-- 创建学生表
CREATE TABLE students (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    course_id INT,
    FOREIGN KEY (course_id) REFERENCES courses(id)
);
-- 创建课程表
CREATE TABLE courses (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    student_id INT,
    FOREIGN KEY (student_id) REFERENCES students(id)
);