How to create a user and grant permissions in PostgreSQL?

To create a user and grant permissions in PostgreSQL, you can follow these steps:

1. Connect to the PostgreSQL database as a superuser.

sudo -u postgres psql

1. Create a new user:

CREATE ROLE new_user WITH LOGIN PASSWORD 'password';

1. Grant database access permissions to new users.

GRANT CONNECT ON DATABASE database_name TO new_user;

1. Grant all permissions of specific databases to new users.

GRANT ALL PRIVILEGES ON DATABASE database_name TO new_user;

1. Grant new users permission to SELECT, INSERT, UPDATE, and DELETE on specific table.

GRANT SELECT, INSERT, UPDATE, DELETE ON table_name TO new_user;

1. If necessary, new users can be granted additional specific permissions, such as creating databases, creating tables, and so on.

ALTER ROLE new_user CREATEDB;

1. Exit from PostgreSQL:

\q

New users have been created and granted permissions now. You can use the new user to log in to the PostgreSQL database and perform the necessary operations.