Operating system: Ubuntu

Run the following command to create a database named mydb

createdb mydb

Get an error: PSQL: fatal: role “Terry” does not exist. Terry is my machine name. There is no role named Terry in the PostgreSQL database, so this error will be reported. Just add the – U parameter to specify an existing role, so I change the above command to:

createdb mydb -U postgres

Get another error: PSQL: fatal:   Peer authentication failed for user “Postgres”. The solution is as follows:

1. Run the following command to edit PG_ Hba.conf file

sudo gedit /etc/postgresql/9.1/main/pg_hba.conf

2. Will

# Database administrative login by Unix domain socket
local   all             postgres                                peer

Change to

# Database administrative login by Unix domain socket
local   all             postgres                                trust

3. After saving, execute the following command to reload the configuration file:

sudo /etc/init.d/postgresql reload

Then execute CREATEDB mydb1 – u Postgres, and the mydb1 database has been successfully created