From: Sumeet <asumeet@gmail.com>
To: pgsql-sql@postgresql.org
Subject: selecting random row values in postgres
Date: Fri, 23 Feb 2007 14:29:13 -0500
Message-ID: <7539aebb0702231129s48399f26r8881c6eff81b0708@mail.gmail.com> (raw)
Hi all,
I'm trying to write a query to select random values from a set of 'GROUP
BY'
....see the scenario below to understand the problem here (the actual
problem cannot be discussed here so i'm taking an example scenario)
Assume there is a table
id | name | year_of_birth
query: I want to select for each year_of_birth a random name.
--> so i do a group by year_of_birth, now i have a set of names, is there
any function to select just one name from these set of names.
The current approach i'm using to solve this problem is
1) getting these names in a single string using a custom function
'group_concat'
2) Convert the single string into an array
3) use postgresql random function to generate a random number
4) us the random number to select a element from the array previously
created.
The solution is there but it's kinda hack, is there any other better way of
solving this problem.
Thanks,
Sumeet
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Cc: asumeet@gmail.com
Subject: Re: selecting random row values in postgres
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