Missing the mysql2 gem. Add it to your Gemfile: gem 'mysql2'

Question

Versions

• ruby 1.9.2-p290
• rails 3.0.9
• mysql2-0.2.13 under rvm
• ubuntu 11.04

gem installed with "gem install mysql2 -v '< 0.3' ". All dependencies were met.

rails & 'rails c' are working fine.

I need to run a script outside of rails environment using activerecord 3.0.9. When I run the script this is the output:

======================

/home/ross/work/x/library/models.rb:27:in `eval': !!! Missing the mysql2 gem. Add it to your Gemfile: gem 'mysql2' (RuntimeError)
    from /home/ross/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.0.9/lib/active_record/connection_adapters/mysql_adapter.rb:19:in `mysql_connection'
    from /home/ross/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.0.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `new_connection' ....

=======================

Clearly the gem is there, because rails works.

Don't know why the gem isn't found when running a script?

Can anyone pls shed some light on the issue?

Regards Ross

Answer 1

In case it helps anyone, in my case I had forgotten to change the adapter in database.yml to mysql2 for the production database, the Gemfile was OK (upgrading from rails 2.3.4 to 3.0.9).

Answer 2

Check your database.yml first

You have something like this:

development:
  adapter: mysql
  encoding: utf8
  ...

To solve your problem you need replace mysql to mysql2.

Correct version of database.yml

development:
  adapter: mysql2 
  encoding: utf8
  ...