From: Michael Neumann <neumann@...>
Date: 2001-12-15T00:14:51+09:00
Subject: [ruby-talk:28508] Re: how can this work correctly?

Jack Dempsey wrote:
> hi all,
> 
> just cruising through the standard example the comes with the Ruby
> DBI...i'm getting an error at this part:
> 
> puts "selecting..."
>     dbh.select_all('select * from simple01') do
>       p row
>     end

Oops, I though I fixed that. Correctly it should look like this:

  puts "selecting..."
  dbh.select_all('select * from simple01') do | row |
    p row
  end

> it can't find row...which makes sense to me, but this is verbatim code
> from the docs which come with the DBI...if i make it do |x| p x it'll
> work, but is this supposed to work and i'm missing something?
> is there any way to do it even shorter than this
> 
> puts "selecting..."
>     dbh.select_all('select * from simple01') do |x| p x end

To output all rows, just use the non code-block version of method select_all. 

  p dbh.select_all('select * from simple01')

I think there's no shorter way, not even in Perl ;-)

Alternatively use { and } instead of "do" and "end":

  dbh.select_all('select * from simple01') {|x| p x}

> something like the $_ var in perl...i know ruby has $_, but seems
> different...

I don't think it would be a good idea to assign $_ before yielding
control to the specified code block. And, writing half a dozen more
characters shouldn't be a problem.

Regards,

  Michael

-- 
Michael Neumann
merlin.zwo InfoDesign GmbH
http://www.merlin-zwo.de