ActiveRecord::AdapterNotSpecified database configuration does not specify adapter

You didn't show the command causing this query, but this could happen if you pass a string and not a symbol.

For example:

irb(main):001:0> ActiveRecord::Base.establish_connection("#{Rails.env}")ActiveRecord::AdapterNotSpecified: database configuration does not specify adapter

But then if you use a symbol, it will work.

irb(main):001:0> ActiveRecord::Base.establish_connection("#{Rails.env}".to_sym)=> #<ActiveRecord::ConnectionAdapters::ConnectionPool:0x007f2f484a32a0 #....

For you app to work locally you need to:

1. Install Postgresql on your machine
2. Create a database for your development needs (let's call it my_app_development)

3. Change your database.yml to:

   default: &default  adapter: postgresql  encoding: unicode  # For details on connection pooling, see rails configuration guide  # http://guides.rubyonrails.org/configuring.html#database-pooling  pool: 5development:  <<: *default  database: my_app_development

4. run rake db:migrate

Your database.yml should look something like this:

default: &default  adapter: postgresql  encoding: unicode  # For details on connection pooling, see rails configuration guide  # http://guides.rubyonrails.org/configuring.html#database-pooling  pool: 5  username: my_username  password: my_passworddevelopment:  <<: *default  database: "development_database_name"test:  <<: *default  database: "test_database_name"production:  <<: *default  database: "production_database_name"

Edit development_database_name to your local database name.Also edit my_username and my_password to your correct db username and password.