From: Carlos <angus@...>
Date: 2004-07-22T02:39:41+09:00
Subject: Re: ruby postgresql question

[Mark Firestone <hash_bang@retrobbs.org>, 2004-07-21 17.45 CEST]
> Well, messages get deleted, but the message numbers in the table don't
> change.  The message numbers (when you are reading them) *do* change because
> they are always 1..<highest message> so the system needs to know which
> actual message to pull up when you type it's number in.  They won't be the
> same, after one message is deleted.  So I am doing a ...
> 
> 
>  for row in @db.query("SELECT number FROM #{table} ORDER BY number")
>   hash << row[0].to_i
>  end
> 
> and making an array, full of message numbers.  A lookup table.  So I can
> look up which message to pull up.

In postgresql you can use the OFFSET and LIMIT modifiers. For example
	SELECT * FROM table ORDER BY number OFFSET #{nth_row} LIMIT 1
retrieves the nth row.

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