Answers for "command to add username and password to postgresdb"

set username and password for postgresql database

sudo -u postgres psql -c "ALTER USER postgres PASSWORD 'postgres';"

How do I add a user to a postgres database? cli

GRANT ALL PRIVILEGES ON DATABASE yourdbname TO youruser;

How do I add a user to a postgres database? cli

psql=# grant all privileges on database <dbname> to <username>