mysql - 如何正确按月份对sql查询结果排序？

Question

我正在处理下面的代码:

SELECT tbl.y YEAR, group_concat(month_posts SEPARATOR '-') dates
    FROM (
        SELECT YEAR(p.post_date) y, MONTH(p.post_date) m, concat(MONTH(p.post_date), ':', group_concat(p.id ORDER BY p.post_date ASC)) month_posts
        FROM prt_posts p    
        WHERE (p.post_status = 'publish' OR p.post_status = 'future') 
            AND p.post_type = 'event'
            AND p.post_date <= DATE('2016-12-31 00:00:00')
        GROUP BY y, m
        ORDER BY y, m ASC
     ) tbl
GROUP BY tbl.y
ORDER BY tbl.y DESC

结果是这样的:

year | dates
-------------------------------------------------------------------
2016     | 11:121,122-12:117,118
-------------------------------------------------------------------
2015     | 1:128-12:138-2:139-3:129-4:130-5:131-6:132-7:133-8:119-9:134
-------------------------------------------------------------------

除了日期顺序之外，一切都很好。正如你在第二行看到的，它是 1, 12, 2, 3, 等等...而它应该是 1, 2, 3, 4, 等等.. 它以字符串而不是数字的形式排序。

如何解决？

Answer 1

已经找到答案:我可以通过将第一行更改为这样进行排序:

SELECT tbl.y YEAR, group_concat(month_posts **ORDER BY tbl.m DESC** SEPARATOR '-') dates