MySQL-SELECT语句执行顺序

发表于： 2023-10-06

字数： 250 阅读：≈ 1分钟

总结摘要

MySQL SELECT Execution Order

SELECT语句执行顺序

WITH (CTE, COMMON TABLE EXPRESSIONS)
FROM
ON
JOIN
WHERE
GROUP BY
HAVING
SELECT, WINDOW FUNCTION
SELECT DISTINCT
UNION, INTERSECT, EXCEPT
ORDER BY
LIMIT, OFFSET
FOR UPDATE, FOR NO KEY UPDATE, FOR SHARE, FOR KEY SHARE

Window functions are permitted only in the select list and ORDER BY clause. Query result rows are determined from the FROM clause, after WHERE, GROUP BY, and HAVING processing, and windowing execution occurs before ORDER BY, LIMIT, and SELECT DISTINCT.

窗口函数仅在 select list 和 ORDER BY 子句中允许使用。查询结果行由 FROM 子句确定，在 WHERE、GROUP BY 和 HAVING 处理之后，窗口执行发生在 ORDER BY、LIMIT 和 SELECT DISTINCT 之前。