编辑代码

CREATE DATABASE zhangsan;
USE zhangsan;

CREATE TABLE students (
    student_id INT PRIMARY KEY AUTO_INCREMENT,
    student_name VARCHAR(50) NOT NULL,
    age INT,
    gender VARCHAR(10)
);

CREATE TABLE courses (
    course_id INT PRIMARY KEY AUTO_INCREMENT,
    course_name VARCHAR(100) NOT NULL,
    teacher_name VARCHAR(50)
);

CREATE TABLE enrollments (
    enrollment_id INT PRIMARY KEY AUTO_INCREMENT,
    student_id INT,
    course_id INT,
    FOREIGN KEY (student_id) REFERENCES students(student_id),
    FOREIGN KEY (course_id) REFERENCES courses(course_id)
);

CREATE TABLE teachers (
    teacher_id INT PRIMARY KEY AUTO_INCREMENT,
    teacher_name VARCHAR(50) NOT NULL,
    department VARCHAR(50)
);