嗨，大家好，我是东哥，今天我们要聊一聊那种长得像“论文”的SQL查询。
要是你也曾被这种巨无霸SQL搞得头昏脑涨，那你肯定会对这篇文章有共鸣。
如图：是不是已经头昏脑胀了？
咱们就借着这张令人瞠目结舌的SQL截图，来细细剖析一下这背后的门道。
首先，看看这张图，我只能说“这哪里是SQL啊，这简直是SQL界的史诗级论文！” 😱
-- 原始SQL（略作简化）SELECT a.name, b.salary, c.department_nameFROM employees aJOIN salaries b ON a.employee_id = b.employee_idJOIN departments c ON a.department_id = c.department_idWHERE a.status = 'ACTIVE'AND b.salary > (SELECT AVG(salary) FROM salaries WHERE department_id = c.department_id)ORDER BY b.salary DESC;
-- 创建临时表/视图CREATE VIEW avg_salaries ASSELECT department_id, AVG(salary) AS avg_salaryFROM salariesGROUP BY department_id;-- 使用视图简化主查询SELECT a.name, b.salary, c.department_nameFROM employees aJOIN salaries b ON a.employee_id = b.employee_idJOIN departments c ON a.department_id = c.department_idJOIN avg_salaries d ON c.department_id = d.department_idWHERE a.status = 'ACTIVE'AND b.salary > d.avg_salaryORDER BY b.salary DESC;
-- 筛选出所有在职员工SELECT a.name, b.salary, c.department_nameFROM employees a-- 获取员工薪资信息JOIN salaries b ON a.employee_id = b.employee_id-- 获取员工所在部门信息JOIN departments c ON a.department_id = c.department_id-- 获取部门平均薪资JOIN avg_salaries d ON c.department_id = d.department_id-- 筛选薪资高于部门平均值的员工WHERE a.status = 'ACTIVE'AND b.salary > d.avg_salaryORDER BY b.salary DESC;
# 结语
对编程、职场感兴趣的同学，可以链接我，微信：coder301 拉你进入“程序员交流群”。
