How to create with the postgres database

 step 01 :: Basic Rails Command to create a rails application with basic api and database postgres.

rails new simple_rest_api --api --database=postgresql 

In this we have add the postgres database and when we use the postgres database then we create and migrate this postgres in our application first.

step 02 : for this we create and migrate the database ::

default aur development mein change hoga production mein change nai hoga

In database.yml We do this :: 

default: &default

  adapter: postgresql

  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

  timeout: 5000

  username: postgres

  password: postgres

  host: localhost

development:

  <<: *default

  database: new_data_dev

test:

  <<: *default

  database: new_data_test

Note : we have add these three options  above dark and bold :: username and password and localhost

step 03 ::  rake db:create and rake db:migrate    

These are the command to create and migrate the postgres database in our rails application.

Important Point to remeber by rinku sir ::

pg gem lagana padhega 

adapter mein bhi postgres likhna hoga 

and default aur development mein change karna hoga bus production mein nai karna hai