How to configure a Database in sqlite3 with a Ruby on Rails project

A 'sqlite3' gem should be in gemfile, By default rails added a gem 'sqlite3' in your gem file, when we generate a new rails app.

put the following code in your config/database.yml file :

development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000
test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000
production:
  adapter: sqlite3
  database: db/production.sqlite3
  pool: 5
  timeout: 5000

Open config/database.yml

Edit setting: change username/password and database name for the development environment with you Sqlite database and restart server

Eg:

  development:
    adapter: sqlite3
    encoding: utf8
    database: [DB name]
    username: [your username]
    password: [your password]
    host: [host name]

Make sure that gem file contains gem 'sqlite3'

In config/database.yml

 development:
   adapter: sqlite3
   database: db/development.sqlite3
   pool: 5
   timeout: 5000

When you create a new rails project, you can specify which database you want to use, example:

rails new your_app_name --database=sqlite3

this will directly generate this configuration under config/database.yml:

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

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