How to sample database

In postgresql, one way to take a random sample is using the random()
function with a limit on the number of rows returned. It is something
like:

    select * from mydb
    order by random()
    limit 100;

Perhaps mysql has a similar RANDOM() function that can be used for
sorting by a random field. 

Loren

Bernardo Rangel Tura <tura at centroin.com.br> writes:
Subject: Re: [R] How to sample database
From: Bernardo Rangel Tura <tura at centroin.com.br>
Cc: r-help at stat.math.ethz.ch
Date: 13 Nov 2002 19:30:19 +0100

Dear R-masters!

I have a database with 2400 patients and I need make a sample with 90 subjects.
How to I make a random sample in this data base with R?

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