Rails Database yml examples for postgres sqlite and mysql

database.yml.myql

# Install the MySQL gem:
# gem install mysql2

default: &default
  adapter: mysql2
  encoding: utf8mb4
  reconnect: false
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: root
  password:
  socket: /tmp/mysql.sock

development:
  <<: *default
  database: app_name_development

test:
  <<: *default
  database: app_name_test

staging:
  <<: *default
  database: app_name_staging

production:
  <<: *default
  database: app_name_production

database.yml.postgresql

# Install the pg gem:
# gem install pg

default: &default
  adapter: postgresql
  encoding: unicode
  host: localhost
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: postgres
  password:

development:
  <<: *default
  database: app_name_development

test:
  <<: *default
  database: app_name_test

staging:
  <<: *default
  database: app_name_staging

production:
  <<: *default
  database: app_name_production

database.yml.sqlite

# SQLite version 3.x
#   gem install sqlite3

default: &default
  adapter: sqlite3
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000

development:
  <<: *default
  database: db/development.sqlite3

# 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
  database: db/test.sqlite3

staging:
  <<: *default
  database: db/staging.sqlite3

production:
  <<: *default
  database: db/production.sqlite3