Ah ha! Much.... thanks. It sure is great to have all you rocket scientists
on the list to help me get up to speed :-)
> From: "Marc Campeau" <[EMAIL PROTECTED]>
> Reply-To: [EMAIL PROTECTED]
> Date: Fri, 31 May 2002 12:45:09 -0400
> To: <[EMAIL PROTECTED]>
> Subject: RE: [CFTALKTor] random selection from database
>
> Hi Karl,
>
>> This may be a dumb question but that's never stopped me before so,...
>
> Never a dumb question, it usually is unclear/absent explanations.
>
> 1) why the order by if you're only getting one item?
> The order by is there to sort the result set by the random column ensuring
> that the 1st row is actually not the first one found in the DB but the first
> random one. Without the order by the select would probably return the same
> 1st row for every call.
>
>
> 2) why the tickcount part?.... what's it do?
> Well, the rand function needs a seed to initialize and ususally it is better
> to use a different number every time you initialize the function other wise
> the function yields the same random series, hence the use of getTickCount().
> Now, as Mike showed, in this case it isn't usefull as the function is called
> on a per row basis on Select using the same tickCount, so using an unique
> integer column on the given table gives a different seed to the rand
> function ensuring a different random series for every call of the function.
>
>
> Hope this is clearer...
>
> Marc
>
>>
>>> From: "Marc Campeau" <[EMAIL PROTECTED]>
>>> Reply-To: [EMAIL PROTECTED]
>>> Date: Fri, 31 May 2002 11:47:52 -0400
>>> To: <[EMAIL PROTECTED]>
>>> Subject: RE: [CFTALKTor] random selection from database
>>>
>>> You could have done this way too. I think it would be better since you
>>> wouldn't be returning the whole table data just to display one row:
>>>
>>> <cfquery name="getPhoto" datasource="dsn">
>>> SELECT TOP 1 items, rand(#getTickCount()#) as orderCol
>>> FROM db table
>>> ORDER BY orderCol #IIF(getTickCount() MOD 2, DE("ASC"), DE("DESC"))#
>>> </cfquery>
>>>
>>> Marc Campeau
>>>
>>>> -----Original Message-----
>>>> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
>>>> Behalf Of Graham Faulkner
>>>> Sent: Friday, May 31, 2002 11:23 AM
>>>> To: [EMAIL PROTECTED]
>>>> Subject: Re: [CFTALKTor] random selection from database
>>>>
>>>>
>>>> Thanks Dan. I ended up doing the following (which seems to work
>>>> fine), but
>>>> wasn't 100% sure if it's the way you were talking about:
>>>>
>>>> <cfquery name="getPhoto" datasource="dsn">
>>>> select items from db table
>>>> </cfquery>
>>>>
>>>> <cfset start = 1>
>>>> <cfset end = getPhoto.recordcount>
>>>> <cfoutput query="getPhoto" startrow="#RandRange(start,end)#"
>> maxrows="1">
>>>> <img src="photos/#photo#">
>>>> </cfoutput>
>>>>
>>>> Blessings,
>>>>
>>>> Graham
>>>>
>>>> ----- Original Message -----
>>>> From: <[EMAIL PROTECTED]>
>>>> To: <[EMAIL PROTECTED]>
>>>> Sent: Friday, May 31, 2002 10:21 AM
>>>> Subject: [CFTALKTor] random selection from database
>>>>
>>>>
>>>>> You could run a query to get the min and max, then use
>> RandRange to get
>>>>> your random id. That should get you started.
>>>>>
>>>>> *******************
>>>>> Hi there,
>>>>>
>>>>> An easy one for a Friday morning...
>>>>>
>>>>> I have a table that lists submitted photos, and would like to have a
>>>> random
>>>>> photo generator that reads from this table in the database.
>> What's the
>>>>> best
>>>>> way to select one random PhotoID from the table and then use
>> it within a
>>>>> <cfoutput> to display a photo?
>>>>>
>>>>>
>>>>>
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