postgresql - How to create postgres database for Rails app manually? -

how can create postgres db rails app in psql, not via rake db:create?

i mean, 1 can write create database project_name, don't know happens in rake task under hood. maybe there lot of additional params.

update

after first answer decided clarify: know how write , use migrations, awesome, question not them. it's rake db:create task , pg adapter.

in other words, want know command in psql equal rake db:create.

if select db on pgadmin iii show sql instructions local things load. importanst if have full text index on. must run them database postgres.