Postgresql Random Rec Set - no Duplicates with Livecode

Rick Harrison harrison at all-auctions.com
Wed Feb 2 20:41:54 CST 2011


Hi again Pierre,

How do I avoid picking duplicates though?

Rick

On Feb 2, 2011, at 6:09 PM, Pierre Sahores wrote:

> 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
>>>> 






More information about the use-livecode mailing list