mysql 排序 简介

1、单列排序

SELECT
    *
FROM
    table_name
ORDER BY
    column_name;

ASC默认升序，降序后面接"DESC"即可。

2、多列排序 

SELECT
    *
FROM
    table_name
ORDER BY
    column_name1,column_name2 DESC;

 首先按`column_name1`字段排序，若`column_name1`相等，则按column_name2排序。

3、自定义排序

SELECT
    *
FROM
    table_name
ORDER BY
    FIELD(`column_name1`,1,5,2),column_name2 DESC;

使用"FIELD()"函数，可指定顺序。

4、其他条件排序

SELECT
    *
FROM
    table_name
ORDER BY
    column_name1 < Now(),IF (
    column_name1 < Now(),column_name1
),column_name1 DESC;

 先按大于等于当前时间升序，再按小于当前时间降序，支持分页。

5、指定字段排序

SELECT
    *
FROM
    table_name
ORDER BY
    column_name1 DESC,column_name1 ASC;

 先按column_name1降序排，再按column_name2升序排。