mysql 修改两张表

-- 创建示例表
CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(50)
);

CREATE TABLE orders (
    id INT PRIMARY KEY,
    user_id INT,
    status VARCHAR(20),
    FOREIGN KEY (user_id) REFERENCES users(id)
);

-- 插入示例数据
INSERT INTO users (id, name) VALUES (1, 'Alice'), (2, 'Bob');
INSERT INTO orders (id, user_id, status) VALUES (1, 1, 'pending'), (2, 2, 'pending');

START TRANSACTION;

UPDATE orders
SET status = 'completed'
WHERE user_id = (SELECT id FROM users WHERE name = 'Alice');

COMMIT;

START TRANSACTION;

UPDATE orders
SET status = 'completed'
WHERE user_id = (SELECT id FROM users WHERE name = 'Alice');

-- 检查是否有记录被更新
SELECT @@ROW_COUNT;

COMMIT;

START TRANSACTION ISOLATION LEVEL SERIALIZABLE;

UPDATE orders
SET status = 'completed'
WHERE user_id = (SELECT id FROM users WHERE name = 'Alice');

COMMIT;