rails api with mongodb raising exception for rails g command

[Sukhbir Singh]

I am developing a rails-api application using mongodb as database. The problem is each time i try rails generators, 

It raises an exception in terminal :--

/user/.gem/ruby/gems/railties-5.1.3/lib/rails/application/configuration.rb:139:in database_configuration': Cannot loadRails.application.database_configuration`:
Could not load database configuration. No such file - ["config/database.yml"] (RuntimeError)

Since, i am using mongodb it does not requires database.yml file.

Expected behavior

It should execute rails g scaffold article2 name:string content:text command without any error.

Actual behavior

Right now it is raising the exception

/user/.gem/ruby/gems/railties-5.1.3/lib/rails/application/configuration.rb:139:in database_configuration': Cannot loadRails.application.database_configuration`:
Could not load database configuration. No such file - ["config/database.yml"] (RuntimeError)

System configuration

Rails version: 5.1.3

Ruby version: 2.4.1

And hence, i want to ask how to solve this problem!!