mysql in字句怎么使用

SELECT column_name(s)
FROM table_name
WHERE column_name IN (value1, value2, ...);

SELECT * FROM users WHERE city IN ('New York', 'Los Angeles', 'Chicago');

SELECT * FROM users WHERE age IN (SELECT age FROM user_ages WHERE age_range = '25-35');

SELECT * FROM users WHERE city IN ('New York', 'Los Angeles');
UNION ALL
SELECT * FROM users WHERE city IN ('Chicago', 'Houston');

SELECT * FROM users WHERE city IN ('New York', NULL); -- 不会返回任何记录

SELECT * FROM users WHERE city IS NULL OR city IN ('New York');

-- 创建一个示例表
CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    city VARCHAR(50)
);

-- 插入一些示例数据
INSERT INTO users (id, name, city) VALUES
(1, 'Alice', 'New York'),
(2, 'Bob', 'Los Angeles'),
(3, 'Charlie', 'Chicago'),
(4, 'David', 'Houston');

-- 使用 IN 字句查询特定城市的用户
SELECT * FROM users WHERE city IN ('New York', 'Los Angeles');