# I need help to connect Postgres and Ruby on Rails Please

**URL:** <https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319>\
**Category:** Rails\
**Created:** [December 5, 2006, 12:07am UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319 "2006-12-05T00:07:47Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 5, 2006, 12:07am UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/1 "2006-12-05T00:07:47Z")

</div>

Hello to everyone, I have a problem that is giving me a headache, and  
trying to do a project in Ruby on Rails and I need to connect with a  
Data Base that is en Postgres, the truth is that I didn’t think that it  
was so hard to connect a DB with postgres because I was working with  
Msyql and everything was easy. This are the thinks that I have install  
in my computer.

1. Debian GNU/Linux, kernel 2.4.27-2-686.
2. Ruby 1.8.2
3. Postgresql 7.4.7-6 sarge1
4. Gems: actionmailer-1.2.5, actionpack-1.12.5, actionwebservice-1.1.6,  
activerecord-1.14.4, activesupport-1.3.1, postgres-pr-0.2.1,  
rails-1.1.6, rake-0.7.1
5. ruby-postgres-0.7.1.tar.tar

The error is that after I install everything that I need, I can’t  
connect with my DB, in my project in the folder /app/models I made a  
archive with the same name off my table, remembering that my real table  
the name is in plural bout in my project in singular, the thinks that I  
wrote look something like this

ActiveRecord::Base.establish\_connection(  
:adapter =\> “postgresql”,  
:host =\> “localhost”,  
:port =\> “5432”,  
:database =\> “mundo”,  
:username =\> “usuario”,  
:password =\> “123456”

)

class Usuario \< ActiveRecord::Base

end

When I try to save something in my DB the error that appears is like  
this:

TypeError in PruebaController#guardar  
can’t convert String into Integer

RAILS\_ROOT: script/…/config/…  
Application Trace | Framework Trace | Full Trace

/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/connection\_adapters/postgresql\_adapter.rb:24:in  
`initialize' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/connection_adapters/postgresql_adapter.rb:24:in`connect’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/connection\_adapters/postgresql\_adapter.rb:24:in  
`postgresql_connection' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/connection_adapters/abstract/connection_specification.rb:251:in`send’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/connection\_adapters/abstract/connection\_specification.rb:251:in  
`connection_without_query_cache=' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/query_cache.rb:54:in`connection=’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/connection\_adapters/abstract/connection\_specification.rb:220:in  
`retrieve_connection' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/connection_adapters/abstract/connection_specification.rb:78:in`connection’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/base.rb:696:in  
`columns' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1969:in`attributes\_from\_column\_definition’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/base.rb:1351:in  
`initialize_without_callbacks' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/callbacks.rb:236:in`initialize’  
app/controllers/prueba\_controller.rb:9:in `new' app/controllers/prueba_controller.rb:9:in`guardar’  
-e:4:in `load' -e:4 /usr/lib/ruby/1.8/webrick/httpserver.rb:104:in`service’  
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /usr/lib/ruby/1.8/webrick/server.rb:172:in`start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:161:in `start' /usr/lib/ruby/1.8/webrick/server.rb:161:in`start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:95:in `start’

Request  
Parameters: {“commit”=\>“Guardar”, “usuario”=\>{“apellido”=\>“GGGGGG”,  
“cedula”=\>“888888”, “nombre”=\>“MMMMM”, “telefono”=\>“5555555”}}  
Show session dump  
flash: !ruby/hash:ActionController::Flash::FlashHash {}

Response  
Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”}

Pleas if someone know how to help me I’ll be grateful.  
From Venezuela. El\_gocho says thank you.  
P.S: sorry if I wrote something wrong, my English writhing is not so  
good.

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 5, 2006, 12:21am UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/2 "2006-12-05T00:21:36Z")

</div>

On 12/4/06, Juan M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ```
> :port => "5432",
> :database => "mundo",
> :username => "usuario",
> :password => "123456"
> 
> ```

In config/database.yml

# Host and port are unnecessary if your database is local.

development:  
adapter: postgresql  
database: mundo  
username: usuario  
password: 123456

Then run ./script/console and do  
class Usuario \< ActiveRecord::Base; end  
Usuario.find(:all)

You should see “select \* from usuarios” in your log/development.log

jeremy

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 5, 2006, 9:10pm UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/3 "2006-12-05T21:10:07Z")

</div>

Jeremy K. wrote:

> On 12/4/06, Juan M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:
> 
> > ```
> > :port => "5432",
> > :database => "mundo",
> > :username => "usuario",
> > :password => "123456"
> > 
> > ```
> 
> In config/database.yml
> 
> # Host and port are unnecessary if your database is local.
> 
> development:  
> adapter: postgresql  
> database: mundo  
> username: usuario  
> password: 123456
> 
> Then run ./script/console and do  
> class Usuario \< ActiveRecord::Base; end  
> Usuario.find(:all)
> 
> You should see “select \* from usuarios” in your log/development.log
> 
> jeremy

Hello my friend, well I try to do what you wrote me bout I still have a  
problem, I changed my  
ActiveRecord::Base.establish\_connection(  
:adapter =\> “postgresql”,  
:host =\> “localhost”,  
:port =\> “5432”,  
:database =\> “mundo”,  
:username =\> “usuario”,  
:password =\> “123456”

)

class Usuario \< ActiveRecord::Base

end

for something like this

ActiveRecord::Base.establish\_connection(  
:adapter =\> “postgresql”,  
:database =\> “mundo”,  
:username =\> “usuario”,  
:password =\> “123456”

)

class Usuario \< ActiveRecord::Base

end

and now I have this problem, when I try to save some data I received a  
javascript error that says “The connection was refused when attempting  
to contact localhost:3000 ”.

Please if you can help I’ll be grateful.  
Thank you. El gocho – From Venezuela

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 5, 2006, 10:26pm UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/4 "2006-12-05T22:26:45Z")

</div>

Juan M. wrote:

> 1. Debian GNU/Linux, kernel 2.4.27-2-686.
> 2. Ruby 1.8.2
> 3. Postgresql 7.4.7-6 sarge1
> 4. Gems: actionmailer-1.2.5, actionpack-1.12.5, actionwebservice-1.1.6,  
> activerecord-1.14.4, activesupport-1.3.1, postgres-pr-0.2.1,  
> rails-1.1.6, rake-0.7.1
> 5. ruby-postgres-0.7.1.tar.tar

Juan,

I believe you have the wrong connector for postgresql, for anything at  
or above 7.4, you need gem: postgres-pr

I see you have gems installed, so you are all set  
gem install postgres-pr

hope this helps

ilan

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 6, 2006, 4:07pm UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/5 "2006-12-06T16:07:43Z")

</div>

I was wondering if there are any real benchmarks using the pure ruby  
postgresql db driver versus the c-bindings one, or if people just  
‘believe’  
one is faster then the other.

(In Java land, pure Java oracle-JDBC driver is actually faster then the  
OCI/native wrapper one (type-4 versus type-2 I think) due to time taken  
in  
the conversion between native c-structs and Java objects. But I’m not  
sure  
Ruby has the same problem…)

On 12/5/06, Jeremy K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> This is not true.
> 
> postgres-pr is the pure-Ruby postgres client
> 
> The other postgres libs are C bindings for the official libpq client.
> 
> The C bindings are more robust, fully featured, and faster.
> 
> jeremy

–  
Virtually, Ned W.

“Settle thy studies, Faustus, and begin…” --Marlowe

Discere docendo…

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 5, 2006, 11:14pm UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/6 "2006-12-05T23:14:55Z")

</div>

On 12/5/06, Ilan B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> I believe you have the wrong connector for postgresql, for anything at  
> or above 7.4, you need gem: postgres-pr
> 
> I see you have gems installed, so you are all set  
> gem install postgres-pr

This is not true.

postgres-pr is the pure-Ruby postgres client

The other postgres libs are C bindings for the official libpq client.

The C bindings are more robust, fully featured, and faster.

jeremy

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 6, 2006, 5:27pm UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/7 "2006-12-06T17:27:05Z")

</div>

2006/12/6, Ned W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> I was wondering if there are any real benchmarks using the pure ruby  
> postgresql db driver versus the c-bindings one, or if people just ‘believe’  
> one is faster then the other.

## Here follow some really dumb benchmarks:

$ cat bm-c.rb

# for ruby-postgres

require ‘postgres’  
require ‘benchmark’  
require ‘common-bm’  
PGconn.translate\_results= ARGV[0] ? true : nil  
bench\_postgres( PGconn.new(‘dbname=template1’) )

$ cat bm.rb

# for postgres-pr

require ‘postgres’  
require ‘benchmark’  
require ‘common-bm’

# initialize(host, port, options, tty, database, user, auth

bench\_postgres(PGconn.new(‘localhost’, 5432, “”, nil, ‘template1’,  
‘nnick’, nil))

$ cat comon-bm.rb  
Q\_S = “select 1::int, 2.0::float, 1234567.8901234::numeric,  
‘text’::text , generate\_series(1,100)”  
Q\_S1 = “select now()::date , generate\_series(1,100)”  
Q\_S2 = “select now()::time , generate\_series(1,100)”  
Q\_S3 = “select now()::timestamptz , generate\_series(1,100)”  
Q\_S4 = “select 2.0::float, 1234567.8901234::numeric, ‘text’::text ,  
generate\_series(1,100), now()”  
N=100

## def bench\_postgres(c) Benchmark.bm do |x| x.report { N.times { c.query(Q\_S) }} x.report { N.times { c.query(Q\_S1) }} x.report { N.times { c.query(Q\_S2) }} x.report { N.times { c.query(Q\_S3) }} x.report { N.times { c.query(Q\_S4) }} end puts c.query(Q\_S4)[0].inspect end

# I put postres-pr to lib/ and postgres.so to libpq/

## $ ruby -I lib bm.rb && ruby -I libpq bm-c.rb && ruby -I libpq bm-c.rb true user system total real 2.920000 0.020000 2.940000 ( 3.263881) 1.940000 0.020000 1.960000 ( 2.219724) 2.010000 0.030000 2.040000 ( 2.307650) 2.010000 0.020000 2.030000 ( 2.315171) 3.030000 0.020000 3.050000 ( 3.477216) [“2”, “1234567.8901234”, “text”, “1”, “2006-12-06 17:57:28.13353+02”] user system total real 0.190000 0.000000 0.190000 ( 0.491127) 0.140000 0.000000 0.140000 ( 0.358521) 0.130000 0.010000 0.140000 ( 0.429801) 0.130000 0.000000 0.130000 ( 0.422406) 0.240000 0.010000 0.250000 ( 0.610914) [“2”, “1234567.8901234”, “text”, “1”, “2006-12-06 17:57:30.752541+02”] user system total real 0.250000 0.010000 0.260000 ( 0.535132) 2.880000 0.030000 2.910000 ( 3.146284) 2.840000 0.080000 2.920000 ( 3.209385) 5.200000 0.010000 5.210000 ( 5.500557) 5.410000 0.050000 5.460000 ( 5.851943) [2.0, #\<BigDecimal:b7d5a93c,‘0.1234567890 1234E7’,16(20)\>, “text”, 1, Wed Dec 06 17:57:49 +0200 2006]

So, it looks like if results aren’t converted from text to Ruby types,  
ruby-postgres is 10 times faster than postgres-pr.

But if ruby-postgres is set to translate values to Ruby types,  
performance drops drastically on Date/Time conversion, but it is  
rather fault of Ruby std libs for date parsing ☹  
Though, if postgres-pr would implement type conversion (and it  
doesn’t), it certainly would be slower - even with support of binary  
format queries ( see  
[http://developer.postgresql.org/pgdocs/postgres/protocol-overview.html](http://developer.postgresql.org/pgdocs/postgres/protocol-overview.html)  
) - implementation in C bindings, with direct access to underlying  
structures of Ruby VALUE should outperform pure Ruby code, I guess.

Maybe, in ruby-postgres 0.8.0, that was going to be released "real  
soon"™ (  
[http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/175563](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/175563)  
) it will be improved 🙂

As for me, I like ruby-postgres better for such features as getting  
value from resulting query row by name ( conn.query(…).first[‘id’]  
), using placeholders in statements (conn.exec(“INSERT INTO foo VALUES  
( $1, $2)”, value\_1, value\_2) ), better support for large objects  
(both lo\_\* and BYTEA), automatic translation to Ruby types (very handy  
when not using magic of ActiveRecord ) etc.

---

<div class="post-metadata">

**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [December 8, 2006, 2:58pm UTC](https://www.ruby-forum.com/t/i-need-help-to-connect-postgres-and-ruby-on-rails-please/78319/8 "2006-12-08T14:58:28Z")

</div>

Lugovoi N. wrote:

> 2006/12/6, Ned W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):
> 
> > I was wondering if there are any real benchmarks using the pure ruby  
> > postgresql db driver versus the c-bindings one, or if people just ‘believe’  
> > one is faster then the other.
> 
> ## Here follow some really dumb benchmarks:
> 
> $ cat bm-c.rb
> 
> # for ruby-postgres
> 
> require ‘postgres’  
> require ‘benchmark’  
> require ‘common-bm’  
> PGconn.translate\_results= ARGV[0] ? true : nil  
> bench\_postgres( PGconn.new(‘dbname=template1’) )
> 
> $ cat bm.rb
> 
> # for postgres-pr
> 
> require ‘postgres’  
> require ‘benchmark’  
> require ‘common-bm’
> 
> # initialize(host, port, options, tty, database, user, auth
> 
> bench\_postgres(PGconn.new(‘localhost’, 5432, “”, nil, ‘template1’,  
> ‘nnick’, nil))
> 
> $ cat comon-bm.rb  
> Q\_S = “select 1::int, 2.0::float, 1234567.8901234::numeric,  
> ‘text’::text , generate\_series(1,100)”  
> Q\_S1 = “select now()::date , generate\_series(1,100)”  
> Q\_S2 = “select now()::time , generate\_series(1,100)”  
> Q\_S3 = “select now()::timestamptz , generate\_series(1,100)”  
> Q\_S4 = “select 2.0::float, 1234567.8901234::numeric, ‘text’::text ,  
> generate\_series(1,100), now()”  
> N=100
> 
> ## def bench\_postgres(c) Benchmark.bm do |x| x.report { N.times { c.query(Q\_S) }} x.report { N.times { c.query(Q\_S1) }} x.report { N.times { c.query(Q\_S2) }} x.report { N.times { c.query(Q\_S3) }} x.report { N.times { c.query(Q\_S4) }} end puts c.query(Q\_S4)[0].inspect end
> 
> # I put postres-pr to lib/ and postgres.so to libpq/
> 
> ## $ ruby -I lib bm.rb && ruby -I libpq bm-c.rb && ruby -I libpq bm-c.rb true user system total real 2.920000 0.020000 2.940000 ( 3.263881) 1.940000 0.020000 1.960000 ( 2.219724) 2.010000 0.030000 2.040000 ( 2.307650) 2.010000 0.020000 2.030000 ( 2.315171) 3.030000 0.020000 3.050000 ( 3.477216) [“2”, “1234567.8901234”, “text”, “1”, “2006-12-06 17:57:28.13353+02”] user system total real 0.190000 0.000000 0.190000 ( 0.491127) 0.140000 0.000000 0.140000 ( 0.358521) 0.130000 0.010000 0.140000 ( 0.429801) 0.130000 0.000000 0.130000 ( 0.422406) 0.240000 0.010000 0.250000 ( 0.610914) [“2”, “1234567.8901234”, “text”, “1”, “2006-12-06 17:57:30.752541+02”] user system total real 0.250000 0.010000 0.260000 ( 0.535132) 2.880000 0.030000 2.910000 ( 3.146284) 2.840000 0.080000 2.920000 ( 3.209385) 5.200000 0.010000 5.210000 ( 5.500557) 5.410000 0.050000 5.460000 ( 5.851943) [2.0, #\<BigDecimal:b7d5a93c,‘0.1234567890 1234E7’,16(20)\>, “text”, 1, Wed Dec 06 17:57:49 +0200 2006]
> 
> So, it looks like if results aren’t converted from text to Ruby types,  
> ruby-postgres is 10 times faster than postgres-pr.
> 
> But if ruby-postgres is set to translate values to Ruby types,  
> performance drops drastically on Date/Time conversion, but it is  
> rather fault of Ruby std libs for date parsing ☹  
> Though, if postgres-pr would implement type conversion (and it  
> doesn’t), it certainly would be slower - even with support of binary  
> format queries ( see  
> [http://developer.postgresql.org/pgdocs/postgres/protocol-overview.html](http://developer.postgresql.org/pgdocs/postgres/protocol-overview.html)  
> ) - implementation in C bindings, with direct access to underlying  
> structures of Ruby VALUE should outperform pure Ruby code, I guess.
> 
> Maybe, in ruby-postgres 0.8.0, that was going to be released "real  
> soon"™ (  
> [http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/175563](http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/175563)  
> ) it will be improved 🙂
> 
> As for me, I like ruby-postgres better for such features as getting  
> value from resulting query row by name ( conn.query(…).first[‘id’]  
> ), using placeholders in statements (conn.exec(“INSERT INTO foo VALUES  
> ( $1, $2)”, value\_1, value\_2) ), better support for large objects  
> (both lo\_\* and BYTEA), automatic translation to Ruby types (very handy  
> when not using magic of ActiveRecord ) etc.

Hello my friends, well I try all the you gays wrote me bout I don’t know  
why I still have the problem, I just want to connect a DB that is in  
Postgres with my project Ruby on Rails, bout nothing seems to work, well  
all that thinks that I had made are:

1. install all these:  
o Debian GNU/Linux, kernel 2.4.27-2-686.  
o Ruby 1.8.2  
o Postgresql 7.4.7-6 sarge1  
o Gems: actionmailer-1.2.5, actionpack-1.12.5, actionwebservice-1.1.6,  
activerecord-1.14.4, activesupport-1.3.1, postgres-pr-0.2.1,  
rails-1.1.6, rake-0.7.1  
o ruby-postgres-0.7.1.tar.tar

2. in my project in the folder /app/models I made a archive with the  
same name off my table, remembering that my real table the name is in  
plural bout in my project in singular, the thinks that I wrote look  
something like this

class Usuario \< ActiveRecord::Base

end

Ok, the first error that I had was these:

TypeError in PruebaController#guardar  
can’t convert String into Integer

RAILS\_ROOT: script/…/config/…  
Application Trace | Framework Trace | Full Trace

/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/connection\_adapters/abstract/connection\_specification.rb:220:in  
`retrieve_connection' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/connection_adapters/abstract/connection_specification.rb:78:in `connection’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/base.rb:696:in  
`columns' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1969:in `attributes\_from\_column\_definition’  
/usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active\_record/base.rb:1351:in  
`initialize_without_callbacks' /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/callbacks.rb:236:in `initialize’  
app/controllers/prueba\_controller.rb:9:in `new' app/controllers/prueba_controller.rb:9:in `guardar’  
-e:4:in `load' /usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service’  
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /usr/lib/ruby/1.8/webrick/server.rb:172:in `start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:161:in `start' /usr/lib/ruby/1.8/webrick/server.rb:161:in `start\_thread’  
/usr/lib/ruby/1.8/webrick/server.rb:95:in `start’

Request  
Parameters: {“commit”=\>“Guardar”, “usuario”=\>{“apellido”=\>“GGGGGG”,  
“cedula”=\>“888888”, “nombre”=\>“MMMMM”, “telefono”=\>“5555555”}}  
Show session dump  
flash: !ruby/hash:ActionController::Flash::FlashHash {}

Response  
Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”}

Well a friend wrote me that the host and port aren’t necessary if my  
data was local and it is, so I changed my connection for something like  
these

ActiveRecord::Base.establish\_connection(  
:adapter =\> “postgresql”,  
:database =\> “mundo”,  
:username =\> “usuario”,  
:password =\> “123456”  
)

class Usuario \< ActiveRecord::Base

end

So after that, I have a different error is a javascript error that says  
“The connection was refused when attempting to contact localhost:3000 ”,  
and the error happens when a try to save something in my DB, my host is  
running because I can see all my web pages bout if I what to save  
something and I click the save button the javascript error appear.

I don’t know if someone in this community can help me, with a tutorial  
or a example the connect Postgres and Ruby on Rails, or maybe tell me  
what thinks do I have to install in what order. Please someone help me I  
don’t want to give-up with these error.

From Venezuela. El\_gocho says thank you.  
P.S: sorry if I wrote something wrong, my English writhing is not so  
good