"ORDER BY'column_name'DESC"，但是字母前的数字需要两个语句? [英] "ORDER BY 'column_name' DESC", but numbers before letters requires two statements?

问题描述

我想在数据库中选择数据并按字母顺序排序，但先是数字，然后是字母.

I want to select data in my database and order it alphabetically but numbers first and then letters.

我的桌子的样品:

                    watch_date
474 1442437 2181257 2015-12-20 Modern Family   3 13 Little Bo Bleep
475 1442437 2189485 2015-12-21 Modern Family   3 14 Me? Jealous?
476 1442437 2209159 2015-12-22 Modern Family   3 15 Aunt Mommy
477 1442437 2237415 2015-12-22 Modern Family   3 16 Virgin Territory
478 1442437 2244103 2015-12-22 Modern Family   3 17 Leap Day
479 1442437 2239817 2015-12-24 Modern Family   3 18 Send Out the Clowns
480 1442437 2305713 2015-12-24 Modern Family   3 19 Election Day
481 1442437 2305715 2016-01-02 Modern Family   3 20 The Last Walt
482 1442437 2247703 2016-01-03 Modern Family   3 21 Planes, Trains and Cars
483 1553656 2656658 unknown    Under the Dome  1  1 Pilot
484 1553656 2779640 unknown    Under the Dome  1  2 The Fire
485 1553656 2821206 unknown    Under the Dome  1  3 Manhunt 

我想使用第四列(带有日期和文字"unknown"(称为"watch_date")的列)进行排序

I want to order it using the fourth column (the column with dates and the text 'unknown' (it's called 'watch_date'))

此列中的数据是文本unknown或格式为YYYY-MM-DD

The data in this column is either the text unknown or a date with the format YYYY-MM-DD

为此，我使用以下查询:

To do this I use the following query:

SELECT * FROM `watched_episodes` ORDER BY `watch_date` + 0 DESC, `watch_date` DESC

我认为+ 0部分为所有结果添加了0，但是当我不添加第二个ORDER BY语句时:

I thought the + 0 part added a 0 to all results, yet when I do not add the second ORDER BY statement:

`watch_date` DESC

它确实将数字(日期)放在字母的前面，但似乎根本没有对日期进行排序.

it does put the numbers (dates) before the letters but it does not seem to sort the dates at all.

推荐答案

嗯，您的查询根本是错误的.由于使用单引号，因此应该给出错误.我假设你打算:

Hmmm, your query is simply wrong. It should be giving an error because of the use of single quotes. I'll assume you intend:

SELECT *
FROM watched_episodes
ORDER BY watch_date + 0 DESC, watch_date DESC;

这似乎是一种奇怪的方法.如果值始终为'Unknown'或YYYY-MM-DD格式的字符串，我会选择:

This seems like a strange method. If the values is always 'Unknown' or a string in YYYY-MM-DD format, I would go for:

ORDER BY (watch_date = 'unknown'),  -- USE `DESC` to put `unknown` first
         watch_date DESC

这篇关于"ORDER BY'column_name'DESC"，但是字母前的数字需要两个语句?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！