示例
示例
SELECT id, dept_id, salary,
AVG(salary) OVER w AS dept_avg,
MAX(salary) OVER w AS dept_max,
salary - AVG(salary) OVER w AS diff
FROM employees
WINDOW w AS (PARTITION BY dept_id);| 语法 | WINDOW 名称 AS (定义)，可定义多个 |
|---|---|
| 作用 | 同一查询内复用，改一处全生效 |
| 顺序 | 每个窗口函数都可以引用命名窗口并追加 ORDER BY（部分数据库限制较多） |