How to change the database in a Rails application - mysql

Question

The database of my Rails application is SQLite3, but I want to change it to MySQL. What do I need to do to change it in my application?
This is database.yml from my application:
# SQLite. Versions 3.8.0 and up are supported.
# gem install sqlite3
#
# Ensure the SQLite 3 gem is defined in your Gemfile
# gem 'sqlite3'
#
default: &default
adapter: sqlite3
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
timeout: 5000
development:
<<: *default
database: db/development.sqlite3
test:
<<: *default
database: db/test.sqlite3
production:
<<: *default
database: db/production.sqlite3

Answer 1

You need to update the adapter to MySQL2 and add your credentials. For instance:
development:
adapter: mysql2
encoding: utf8mb4
database: development
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
username: root
password: password
socket: /tmp/mysql.sock
Look at the offical documentation for more information.
Here is it with defaults:
default: &default
adapter: mysql2
timeout: 5000
encoding: utf8mb4
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
socket: /tmp/mysql.sock
development:
<<: *default
database: development
username: <%= ENV.fetch("username") %>
password: <%= ENV.fetch("password") %>
test:
<<: *default
database: test
username: username
password: password
production:
<<: *default
database: production
username: <%= ENV.fetch("username") %>
password: <%= ENV.fetch("password") %>
You can also encode username and password in the database like this:
mysql://<username>:<password>#<host>:<port>/<db_name>
and then set host. Don't put username and password in your database.yml file.