Order by RAND()

Question

I have a Tinder like script with images of males and females. On every page the script shows one person and the user can go to the next person. In my situation I'm using:

ORDER BY rand(".preg_replace('/\D/', '', Cookie::get('random')).")

So ordering by a random number I put in the cookie.

I have a lot of males and few females. How can I influence the RAND() function to show more females?

Check your privilege; there are more genders than this. Your website violates discrimination laws in several jurisdictions. Hope you have a good lawyer! :) — Lightness Races in Orbit, Jun 10 '14 at 11:29

nl-x · Accepted Answer · 2014-06-10T12:20:47.467

3

First start with just doing order by rand(), and remove the stuff between (). That will also give you a random order.

Second, if you want as many men as women, or some kind of ratio, you need to UNION two queries. One query where you get random men, and another query where you get random women.

edit:

Another way to go about it is do do:

order by (if(gender='f',rand()/5,rand())

when 1:5 is the ratio woman/man.

edited Jun 10 '14 at 12:20

answered Jun 10 '14 at 10:33

nl-x

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If I remove the stuff in the (), I get duplicate results, so I can't do that. – Nathaniel Jun 10 '14 at 10:40
1

@Nathaniel: That's a new problem, and one [you can solve](http://lists.mysql.com/mysql/203257) instead of just avoiding this improvement entirely. – Lightness Races in Orbit Jun 10 '14 at 11:32
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@Nathaniel In no way can just removing the stuff in `rand()` avoid/add duplicates. `order by` only affects your ordering. – nl-x Jun 10 '14 at 12:17

Order by RAND()

1 Answers1