I use Windows 7 on my own home computer. I have installed PostgreSQL and now I would like to create an database.
I tried with
createdb mydatabase but I got this error message:
createdb: could not connect to database postgres: FATAL: role "Jonas" does not exist
I have also tried to create a role "Jonas" with
createuser Jonas but I got the same error, even if I was logged in as Administrator in PowerShell.
How can I create a PostgreSQL database on my Windows 7 machine?