I want to create my Rails application with MySQL, because I like it so much. How can I do that in the latest version of Rails instead of the default SQLite?
19 Answers
If you already have a rails project, change the adapter in the config/database.yml
file to mysql
and make sure you specify a valid username and password, and optionally, a socket:
development:
adapter: mysql2
database: db_name_dev
username: koploper
password:
host: localhost
socket: /tmp/mysql.sock
Next, make sure you edit your Gemfile to include the mysql2 or activerecord-jdbcmysql-adapter (if using jruby).
If you have not created your app yet, just go to cmd(for windows) or terminal(for linux/unix) and type the following command to create a rails application with mysql database:
$rails new <your_app_name> -d mysql
It works for anything above rails version 3. If you have already created your app, then you can do one of the 2 following things:
- Create a another_name app with mysql database, go to cd another_name/config/ and copy the database.yml file from this new app. Paste it into the database.yml of your_app_name app. But ensure to change the database names and set username/password of your database accordingly in the database.yml file after doing so.
OR
- Go to cd your_app_name/config/ and open database.yml. Rename as following:
development:
adapter: mysql2
database: db_name_name
username: root
password:
host: localhost
socket: /tmp/mysql.sock
Moreover, remove gem 'sqlite3' from your Gemfile and add the gem 'mysql2'
On new project, easy peasy:
rails new your_new_project_name -d mysql
On existing project, definitely trickier. This has given me a number of issues on existing rails projects. This kind of works with me:
# On Gemfile:
gem 'mysql2', '>= 0.3.18', '< 0.5' # copied from a new project for rails 5.1 :)
gem 'activerecord-mysql-adapter' # needed for mysql..
# On Dockerfile or on CLI:
sudo apt-get install -y mysql-client libmysqlclient-dev
database.yml
# MySQL. Versions 5.1.10 and up are supported.
#
# Install the MySQL driver
# gem install mysql2
#
# Ensure the MySQL gem is defined in your Gemfile
# gem 'mysql2'
#
# And be sure to use new-style password hashing:
# https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html
#
default: &default
adapter: mysql2
encoding: utf8
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
host: localhost
database: database_name
username: username
password: secret
development:
<<: *default
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
<<: *default
# As with config/secrets.yml, you never want to store sensitive information,
# like your database password, in your source code. If your source code is
# ever seen by anyone, they now have access to your database.
#
# Instead, provide the password as a unix environment variable when you boot
# the app. Read http://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full rundown on how to provide these environment variables in a
# production deployment.
#
# On Heroku and other platform providers, you may have a full connection URL
# available as an environment variable. For example:
#
# DATABASE_URL="mysql2://myuser:mypass@localhost/somedatabase"
#
# You can use this database configuration with:
#
# production:
# url: <%= ENV['DATABASE_URL'] %>
#
production:
<<: *default
Gemfile:
# Use mysql as the database for Active Record
gem 'mysql2', '>= 0.4.4', '< 0.6.0'
you first should make sure that MySQL driver is on your system if not run this on your terminal if you are using Ubuntu or any Debian distro
sudo apt-get install mysql-client libmysqlclient-dev
and add this to your Gemfile
gem 'mysql2', '~> 0.3.16'
then run in your root directory of the project
bundle install
after that you can add the mysql config to config/database.yml as the previous answers