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From Steve Terrell <sterr...@oculus360.us>
Subject Re: Random rows
Date Tue, 28 Mar 2017 22:10:01 GMT
Here's what I do in one of my applications.  A two-step process minimum
(three if you get a total row count first):

upsert into DEMO(KEY_FIELD_1,KEY_FIELD_2,"random_sample" boolean) select
KEY_FIELD_1,KEY_FIELD_2,(rand()<(50.0/1000))

Where in this example, I want to randomly select 50 rows from a table
containing 1,000 rows. It will only be approximate.  The ".0" is added to
make sure the division does not yield an int.  You can replace the division
with any ratio you like.

Anyway, after doing the above upsert select, I can query for the random
rows like this:

select * from DEMO("random_sample" boolean) where "random_sample" is true

That's the best I could come up with using Phoenix 4.6.0.

Hope this helps,
    Steve

On Tue, Mar 28, 2017 at 2:18 PM, Mike Prendergast <
mikeprendergast@iotait.com> wrote:

> Any suggestion on how I could obtain a random set of rows in Phoenix? I'm
> looking to get a sample set spread across all regions for testing purposes.
> Thanks in advance
>
> Michael Prendergast
> *iota IT*
> Vice President / Software Engineer
> (cell)     703.594.1053 <(703)%20594-1053>
> (office)  571.386.4682 <(571)%20386-4682>
> (fax)     571.386.4681 <(571)%20386-4681>
>
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