RuntimeError with mysql2 and rails3 (bundler)

mysql ruby-on-rails bundler

63,347

Solution 1

I had the same error after upgrading from Ubuntu 11.10 to 12.04. This is how I fixed the problem:

gem uninstall mysql2
bundle

I think the key here is the 'native extensions' -- I suppose when I installed last, I was using a different version of mysql.

Installing mysql2 (0.3.11) with native extensions

Solution 2

I was getting the same error while using rails 3.0.7 and mysql2 0.3.2. The solution, which I found here, is to use an older version of mysql2. Thus edit your gemfile to

gem 'mysql2', '< 0.3'

and run

bundle install

Solution 3

Also need to change adapter from mysql to mysql2 in database.yml as said here Install mysql2 gem on Snow Leopard for Rails 3 with rvm

From:

development: adapter: mysql

To:

development: adapter: mysql2

Solution 4

Did you include the mysql2 gem in your gemfile instead of the old mysql gem, and ran bundle install afterwards?

Solution 5

If you're using rvm, and possibly added mysql2 outside of rvm, try these steps: Confirm that your Gemfile says:

gem 'mysql2'

or for Rails2.x:

gem 'mysql2', '~> 0.2.11'

then:

$ cd RAILS_ROOT
$ gem uninstall mysql2

Select gem to uninstall:
 1. mysql2-0.2.11
 2. mysql2-0.3.6
 3. All versions
> 3 # select "All versions"
$ rvm gemset install mysql2
$ bundle install

Now rails should start properly.

View more solutions

63,347

Swistak

Wannabe *

Updated on January 05, 2020

Comments

Swistak over 4 years
I get this error
```
`establish_connection': Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (no such file to load -- active_record/connection_adapters/mysql2_adapter) (RuntimeError)
  from /opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-
```
Here is dump of whole error and my config and gemfile.
- maniempire over 12 years
  
  I faced the same problem and after several analysis, i am able to successfully install the mysql2 on windows with rails3. The process i followed is given in the following blog post. kyybaventures.com/blog/installing-mysql2-gem-ruby-rails-wind‌ows Hope, it will be useful to solev the above problem. Mani
Senthil Kumar over 13 years

This might help someone. stackoverflow.com/questions/3608287/…
fullstacklife over 13 years

I was having this problem as I was installing the mysql2 gem manually. Then I used it as you said in the gemfile and ran bundle install. It loaded up, but I I got the could not connect to mysql.sock error. So I THEN ran env ARCHFLAGS="-arch i386" gem install mysql2 --version 0.2.6 -- --with-mysql-config=/usr/local/mysql/bin/mysql_config (i am on a mac pro) and this seemed to solve my problems. Ran rails s and hey presto..Hope this helps someone else out :)
Tomasz Iniewicz about 13 years

this clued me in. I ran "sudo gem install mysql2" and it worked. Thanks!
TrinitronX almost 13 years

This one fixed it for me on Ubuntu 10.04!! If using RVM, you can also use: rvm gem install mysql2 --version=0.2.7, and add the above line to your Gemfile.
David Ortinau almost 13 years

I had this exact same issue today, going up to 3.1 and back down to 3.0.7. This was the fix.
Kevin almost 13 years

except those versions of mysql2 have blocking issues in large sites
Barry almost 13 years

Same here - apparently mysql2 > 3.0 does not load the AR adapter pronto
Gabe Martin-Dempesy almost 13 years

Manual gem management outside of a Gemfile is not recommended. It is prone to dependency issues for other developers or deployment.
Nicolas Raoul almost 13 years

That fixed the problem. On Ubuntu 11.04 Natty
Tass over 12 years

Isn't it generally bad practice to install a gem using sudo? stackoverflow.com/questions/2119064/…
Tim Harper over 12 years

For more enlightenment, see the following mysql2 issue on github, which says mysql 0.3.x will only work with rails 3.1 and onward: github.com/brianmario/mysql2/issues/155
Yuval Karmi over 12 years

This should be the selected answer. Excellent!
hoff2 almost 12 years

Still useful for those of us still maintaining Rails 2.3 apps but who want to use mysql2 for its better UTF-8 handling. I don't think Rails < 3 works with mysql2 0.3+
Ms01 over 11 years

Install homebrew if you are using mac osx and then do brew install mysql. After that, bundle install and it should work. :)
stefgosselin about 11 years

@dryprogrammers - Wich I could give you 100+, please put your comment as answer, it is VERY relevant for Ubuntu 12-10 as well. On fully updated Ubuntu 12.10 Precise gitlab would not install. Bump. After many hours (6-8) of searching and trying many things, I tried your mac hack as a last resort. LO AND BEHOLD much as I (cough) don`t really care at all for Macs ... this did it for me now I can go to bed ... happy! :)