Check out example codes for "create and attach user to a postgresql database". It will help you in understanding the concepts better.

Code Example 1

sudo -u postgres psqlpostgres=# create database mydb;postgres=# create user myuser with encrypted password 'mypass';postgres=# grant all privileges on database mydb to myuser;

Code Example 2

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

Code Example 3

GRANT ALL PRIVILEGES ON DATABASE yourdbname TO youruser;

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