rake aborted! no such file to load -- pg (Creating postgre database in rails )

Question

I'm trying to start a rails project with a postgresql database but when i try to create the db with the command:

rake db:create

I'm getting the following error message:

rake aborted! no such file to load -- pg

I'm using mac os X so postgresql is intalled in the /Library folder. I've look around for the pg file but i could not find it and i

Answer 1

If you are using PostgreSQL 9 downloaded from enterprisedb you need to install the pg gem in one of the following way:

If you use rvm use:

env ARCHFLAGS="-arch x86_64" \
  gem install pg -- \
  --with-pg-include=/Library/PostgreSQL/9.0/include/ \
  --with-pg-lib=/Library/PostgreSQL/9.0/lib/

Otherwise use:

sudo env ARCHFLAGS="-arch x86_64" \
  gem install pg -- \
  --with-pg-include=/Library/PostgreSQL/9.0/include/ \
  --with-pg-lib=/Library/PostgreSQL/9.0/lib/

If that doesn't work, we need to know which version of OSX and which version of PostgreSQL.

Answer 2

make sure you have the pg gem installed.

gem install pg

or

include gem pg in your Gemfile and run bundle install if using bundler

Answer 3

All right. Another day, another opportunities.

I found the problem! If you want to install "gem install pg" you need to have the postgres header files on your machine. After I installed Postgres 8.3 via Macports I was also able to install the pg gem. I used this command to install the pg gem:

sudo env ARCHFLAGS='-arch i386' gem install pg

I found the solution in this blog post:

http://flux88.com/blog/installing-postgresql-for-rails-on-mac-os-x/

After reading the post and all the comments, I could resolve the problem.