This question is similar to create database using psql in shell script takes username as db name, but since that doesn't have an accepted answer I'm asking it again here. I've created a user with username myuser and password mypassword:
> psql
psql (11.5)
Type "help" for help.
kurt=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
kurt | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
myuser | | {}
kurt=#
However, if I do psql --username=myuser, I get an error that database "myuser" does not exist:
> psql --username=myuser
psql: FATAL: database "myuser" does not exist
I'm a bit confused by this error message, because according to psql --help, this is a user name, not a database name:
Connection options:
-h, --host=HOSTNAME database server host or socket directory (default: "local socket")
-p, --port=PORT database server port (default: "5432")
-U, --username=USERNAME database user name (default: "kurt")
-w, --no-password never prompt for password
-W, --password force password prompt (should happen automatically)
Any idea what I'm doing wrong? Here is the version of psql I'm using:
> psql --version
psql (PostgreSQL) 11.5
The default user name is your operating-system user name, as is the default database name
If you specify a username, that username is then also assumed as the default for the database name.