From: Steve Litt <slitt@...>
Date: 2006-08-26T02:48:50+09:00
Subject: Can't get ActiveRecord to work with Ruby and Postgres

Hi all,

I'm experimenting with ActiveRecord with Ruby -- no Rails. I installed both 
the Mysql and Postgres (the C one, not the fully Ruby one) database dependent 
drivers. I can use them to manipulate their databases, respectively. I 
installed DBI, and can get it to manipulate both the MySQL and the Postgres 
database, and except for a couple things, do it in a database independent 
way.

I installed ActiveRecord (via an old Rails install), and can get it to 
interact with the MySQL database. However, when I try to get it to interact 
with the Postgres database, I get the following error:

[slitt@mydesk ~]$ ./test2.rb
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/connection_adapters/abstract/connection_specification.rb:79:in 
`establish_connection': database configuration specifies nonexistent pg 
adapter (ActiveRecord::AdapterNotFound)
        from ./test2.rb:5
[slitt@mydesk ~]$

I'll leave my code at the bottom of this email. When I comment out 
the :adapter =>"pg" statement, it works perfectly with MySQL. But when I 
instead comment out the :adapter =>"mysql" statement, it errors out as 
explained earlier.

What steps should I take to identify the cause of this problem?

Thanks

SteveT

#!/usr/bin/ruby
require 'rubygems'
require_gem 'activerecord'

ActiveRecord::Base.establish_connection(
#  :adapter  => "mysql",
  :adapter  => "pg",        # adapter not found error, investigate
  :database => "test",
  :user => "myid"
)

class Rock < ActiveRecord::Base
end

newrow = Rock.new
newrow.rockname = "Bassalt"
newrow.save

puts Rock.find(:first).rockname
puts "Now let's see them all!"
whatever = Rock.find(:all)
whatever.each do |row|
	print row.id, "   ", row.rockname, "\n"
end

Rock.delete_all("rockname = 'Bassalt'")