安装后的PostgreSQL错误

Question

I already have a rails project then i installed Postgresql and pgadmin III , I need to use posgresql in development instead of sqlite and production to use heroku , I followed the answer number two in this question Change from SQLite to PostgreSQL in a fresh Rails project because i just installed Postgresql using synaptic center without making anything else , when i try to create a user i got an error:

createuser dexter
Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) y
Shall the new role be allowed to create more new roles? (y/n) y
createuser: could not connect to database postgres: FATAL:  role "dexter" does not exist

Answer 1

use:

$ sudo -u postgres createuser

To answer your question, from the postgresql documentation :

"If you wish to create a new superuser, you must connect as a superuser, not merely with CREATEROLE privilege. Being a superuser implies the ability to bypass all access permission checks within the database, so superuserdom should not be granted lightly."

Given that the account you are creating is simply for granting your Rails application access, while the ability to create databases makes sense, superuser privileges is not a good idea.