mysql生成不重复数据结构

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    email VARCHAR(100) NOT NULL UNIQUE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

import mysql.connector

try:
    conn = mysql.connector.connect(user='your_user', password='your_password', host='your_host', database='your_database')
    cursor = conn.cursor()
    
    # 检查数据是否存在
    query = "SELECT email FROM users WHERE email = %s"
    cursor.execute(query, ('example@example.com',))
    result = cursor.fetchone()
    
    if not result:
        # 插入数据
        insert_query = "INSERT INTO users (username, email) VALUES (%s, %s)"
        cursor.execute(insert_query, ('example_user', 'example@example.com'))
        conn.commit()
    else:
        print("Email already exists.")
except mysql.connector.Error as err:
    print(f"Error: {err}")
finally:
    if conn.is_connected():
        cursor.close()
        conn.close()