Postgresql Random Rec Set - no Duplicates with Livecode

Pierre Sahores psahores at free.fr
Wed Feb 2 18:09:16 EST 2011


Hi Rick,

SELECT *
FROM table
WHERE condition = true
ORDER BY hashfloat8(random())
LIMIT 10;

Are you sure that the order by + limit clauses used together can't suit exactly your needs ?

Best,

Pierre

Le 2 févr. 2011 à 23:40, Rick Harrison a écrit :

> Hi Pierre,
> 
> What I'm looking to do is to perform the Random pick from the database,
> not reorder my results randomly after I've gotten all records.  I don't think
> the code links below help me to do that.  I've been down this road already.
> 
> Thanks anyways!
> 
> Rick
> 
> On Feb 2, 2011, at 4:29 PM, Pierre Sahores wrote:
> 
>> It's a SQL syntax task, not a revDB one and as soon as the query will be OK, revDB will just handle it as expected.
>> 
>> <http://archives.postgresql.org/pgsql-general/2007-08/msg02034.php>
>> <http://bytes.com/topic/postgresql/answers/857541-random-sample-rows>
>> 
>> Best regards,
>> 
>> Le 2 févr. 2011 à 21:29, Rick Harrison a écrit :
>> 
>>> Hi there,
>>> 
>>> I need to know the best way to get a random subset
>>> of records without duplicates in the resulting record
>>> set using a Postgresql database query with Livecode
>>> on On-Rev.
>>> 
>>> In other words, I don't want to have to get all of the
>>> records in the database first just to be able to pick
>>> out the 21 random records i need, as that seems rather
>>> inefficient.  Assume a couple of thousand records
>>> in the database or more.
>>> 
>>> Thanks for your ideas in advance!
>>> 
>>> Rick
>>> 
>>> _______________________________________________
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>> 
>> --
>> Pierre Sahores
>> mobile : (33) 6 03 95 77 70
>> 
>> www.woooooooords.com
>> www.sahores-conseil.com
>> 
>> 
>> 
>> 
>> 
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> 
> __________________________________
> Rick Harrison
> 
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--
Pierre Sahores
mobile : (33) 6 03 95 77 70

www.woooooooords.com
www.sahores-conseil.com








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