在MySQL中有两列的ORDER BY

Question

I know I can order two columns with

ORDER BY col1 DESC, col2 DESC

for example.

But in my case this doesn't work. I have a MySQL-Query, where I want to display events of the next days ordered by date , BUT also by a column named highlight .

Because there are 3 types of events: TOP-Premium (+++), Premium (++) and Free (+).

Now it orders like this:

-- < example >

7th May 2013

+FREE EVENT
++PREMIUM
+++TOP PREMIUM
+++TOP PREMIUM

--

8th May 2013
(same here as on 7th May 2013)

-- < / end of example >

So, as you can see, it orders by the next date is coming, which is correct! But I want to order the TOP-Premium-Events at the top, followed by the Premium-Events and at least the free events.

The end of my current non-working query is:

ORDER BY e.`date` ASC, e.`highlight` ASC");

I appreciate any help or suggestions!

Answer 1

Uhm,

ORDER BY e.date ASC, e.highlight DESC

?

Answer 2

ORDER BY e.date DESC，e.highlight ASC

Answer 3

Swap two columns - first order by highlight and then by date. You will get sequence like:

Top premium: 7th may
Top premium: 8th may
Premium: 7th may
Premium: 8th may
Free: 7th may
...

Answer 4

ENUMs are represented internally as numbers, in the order that they were listed in the declaration. If you declare a column as ENUM('2', '1', '0') , '2' is stored as 1 , '1' as 2 , and '0' as 3 .

ORDER BY uses those internal numbers, not the labels. If you want to order by the label, rather than the internal number, you have to use CAST() , eg

ORDER BY e.`date` ASC, CAST(e.highlight AS CHAR) ASC

This is one of the reasons why it's usually a bad idea to use numbers as the labels for an ENUM. The MySQL documentation recommends against it.