Posted by J.O. Aho on 01/08/06 14:18

Joe wrote:
> "Stefan Rybacki" <stefan.rybacki@gmx.net> skrev i en meddelelse
> news:42apniF1hejs7U1@individual.net...
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>> Joe wrote:
>>> Hi
>>> I need some help doing a easy php/sql solution to a random selection with
>>> rated stuff.
>>> I have a table like:
>>>
>>> Name Rated
>>> --------------
>>> Thompsen 500
>>> Milla 10
>>> Jensen 1
>>>
>>> Means that the name Thompsen appears 50 times as often as Milla and 500
>>> times as often Jensen.
>>>
>>> I now need some scripting that counts the total ratefactor like
>>> SELECT sum(Rated) FROM Table
>>> In this case 511
>>> And then make a random value between 1 and 511 and then print out the
>>> name,
>>> which in this case will be Thompsen 500 of 511 times (in avg)
>>>
>>> I need a quick way to find a name based on the Rated factors, any help?
>>>
>> 1. get your ratefactor (SELECT sum(rated) FROM table)
>> 2. create a random number between 1 and ratefactor in PHP
>> 3. get the random item (SELECT name FROM table WHERE
>> rated>=created_randomnumber
>> ORDER BY rated, rand() LIMIT 1)
>>
>> Regards
>> Stefan
>>
>
> I think I need some explanation for this :-)
>
> As I see it it will give equal chance of the three names if the random
> number is 1, is that correct?
>
> If that's correct it will not be 1/511 chance of the name Jensen to appear.
>
>
Think you have to use PROCEDURE to be able to do this completely in the SQL,
other wise you could just load everything into the PHP and process it in the
script, of course not the most optimal if there is a lot of rows in the database.
For PROCEDURE in MySQL you need version 5.0 or later.


//Aho

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