mysql 触发器响应删除数据

-- 创建用户表
CREATE TABLE users (
    id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(100)
);

-- 创建订单表
CREATE TABLE orders (
    id INT PRIMARY KEY AUTO_INCREMENT,
    user_id INT,
    amount DECIMAL(10, 2),
    FOREIGN KEY (user_id) REFERENCES users(id)
);

-- 创建AFTER DELETE触发器
DELIMITER $$
CREATE TRIGGER after_user_delete
AFTER DELETE ON users
FOR EACH ROW
BEGIN
    DELETE FROM orders WHERE user_id = OLD.id;
END$$
DELIMITER ;

-- 检查触发器语法
SHOW TRIGGERS;

-- 检查表和列是否存在
DESCRIBE users;
DESCRIBE orders;

-- 检查权限
SHOW GRANTS FOR 'username'@'host';

-- 示例：简化触发器操作
DELIMITER $$
CREATE TRIGGER after_user_delete
AFTER DELETE ON users
FOR EACH ROW
BEGIN
    -- 简化操作，只删除订单
    DELETE FROM orders WHERE user_id = OLD.id;
END$$
DELIMITER ;