ruby - Error when running cmd <rake db:migrate> - "No connection pool with 'primary' found" -

i'm trying set sqlite db sinatra app , running error can't figure out. i've looked related questions none of them have helped.

up point i've run bundle exec rake db:create_migration name=create_budget created migration in db folder.

however when run bundle exec rake db:migrate following error message:

activerecord::connectionnotestablished: no connection pool 'primary' found.

i following tutorial https://learn.co/lessons/sinatra-activerecord-setup

database.yml - instructions did not create in researching error seemed keep coming up. still magic me learn i'm not sure if activerecord requires or not.

 # sqlite version 3.x #   gem install sqlite3-ruby (not necessary on os x leopard) development:   adapter: sqlite3   database: db/development.sqlite3   pool: 5   timeout: 5000  # warning: database defined "test" erased , # re-generated development database when run "rake". # not set db same development or production. test:   adapter: sqlite3   database: db/test.sqlite3   pool: 5   timeout: 5000  production:   adapter: sqlite3   database: db/production.sqlite3   pool: 5   timeout: 5000 

migrate: created db:create_migration

# database migration class createbudget < activerecord::migration[5.1]   def change     create_table :budget |t|       t.string :description       t.string :amount     end   end end 

gemfile:

# frozen_string_literal: true  source 'https://rubygems.org'  git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }  # gem "rails"  gem 'activerecord' gem 'rake' gem 'require_all' gem 'sinatra' gem 'sinatra-activerecord' gem 'slim' gem 'thin'  group :development   gem 'pry'   gem 'shotgun'   gem 'sqlite3'   gem 'tux' end 

file structure - not sure if helpful or not