PostgreSql

psql -h <hostname> -p <port> -U <username> -d <database>
psql -h myhost -p 5432 -U myapplicationuser -d applicationdb

postgresql://<username>:<password>@<hostname>:<port>/<database>
psql postgresql://myapplicationuser:mypass@myhost:1234/applicationdb

\l

\c <db_name>
\c users

\d

\d+ <table_name>

DROP DATABASE <database_name>;

DROP TABLE <table_name>;

CREATE USER <user_name> WITH PASSWORD '<user_password>' SUPERUSER;
ALTER ROLE <user_name> WITH LOGIN;

quit