Role does not exist and unable to create database when using PostgreSQL

Add a username to your database.yml, might as well use your application's name (or some variant of the name) as the username, I'll use app_name as a placeholder:

development:  adapter: postgresql  encoding: utf8  database: app_development  pool: 5  username: app_name  password:

Then create the user (AKA "role") inside PostgreSQL using psql.exe:

$ psql -d postgrespostgres=# create role app_name login createdb;postgres=# \q

The first line is in your terminal, the next two are inside psql. Then do your rake db:create.

The User user is possibly a default but user is already taken for other purposes in PostgreSQL so you'd have to quote it to preserve the case if you wanted to use User as a username:

postgres=# create role "User" login createdb;

You're better off creating one user per-application anyway.

You'll want to do similar things for your test entry in database.yml as well.

PostgreSQL will try to create the database with your account (login) name if a username isn't specified in your config/database.yml. On OS X and Linux you can you see who this is with whoami. Looks like you're using Windows.

Solution A:Create a PostgreSQL user that matches the one it's looking for. For example

createuser --superuser some_user

Solution B:Change the DB user by explicitly setting a username as shown in mu's answer.

If you have a specific account/user on your machine for postgres called postgres for example.

Then executing this command will bring a prompt for you to enter a role name.

sudo -u postgres createuser --interactive

Then doing

rake db:create

Should work!