mysql 设置列默认值

-- 创建表并设置列默认值
CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    email VARCHAR(100),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    status ENUM('active', 'disabled') DEFAULT 'active'
);

-- 插入数据，未指定created_at和status列的值
INSERT INTO users (username, email) VALUES ('john_doe', 'john@example.com');

-- 查询数据
SELECT * FROM users;

-- 检查数据类型
DESCRIBE users;

-- 检查插入语句
INSERT INTO users (username, email, created_at, status) VALUES ('john_doe', 'john@example.com', NOW(), 'active');

-- 检查权限
SHOW GRANTS FOR 'current_user'@'localhost';