面试题：MySQL中IN操作符在复杂查询中的应用

Question

假设有两个表，`employees`表包含字段`employee_id`、`name`、`department_id`，`departments`表包含字段`department_id`、`department_name`。现在要查询出`department_name`为'研发部'或'市场部'的所有员工信息，用MySQL的IN操作符结合连接查询来实现，写出SQL语句。

Answer 1

SELECT e.employee_id, e.name, e.department_id
FROM employees e
JOIN departments d ON e.department_id = d.department_id
WHERE d.department_name IN ('研发部', '市场部');