Ruby on Rails server cannot connect to mysql

Question

everyone. I am trying to set up rails 3 project with mysql as database on macOS X. However, I receive the next error:

/usr/local/bundle/gems/activerecord-3.2.22.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:68:in connection_url_to_hash': undefined method `sub' for nil:NilClass (NoMethodError)

config/database.yml

default: &default
  adapter: mysql2
  pool: 5
  encoding: utf8
  min_messages: warning
  timeout: 5000
  username: root
  password:
  database: heart_development
  host: localhost

Can anyone suggest how to solve this problem?

Answer 1

From the database.yml which you have shared and the logs posted it seems like it is unable to find the path where the database is located.

Change the database.yml to

  default: &default
  adapter: mysql2
  pool: 5
  encoding: utf8
  min_messages: warning
  timeout: 5000
  username: root
  password:
  database: heart_development
  host: localhost

Specified host for which the database has to connect to.

Answer 2

I commented environmental variable DATABASE_URL in my .env file. Also I configured my database.yml in the next way:

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: heart_development
  pool: 5
  username: root
  password:
  host: localhost
  port: 3306

test:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: heart_test
  pool: 5
  username: root
  password:
  host: localhost
  port: 3306

production:
  adapter: mysql2
  encoding: utf8cm
  reconnect: false
  database: heart_production
  pool: 5
  username: root
  password:
  host: localhost
  port: 3306