Below are several useful database commands
sudo -u postgres psql
postgres=# \l - lists all databases
postgres=# \c webclient - selects ‘webclient’ database
webclient=# \dt - shows a list of tables
webclient=# select * from camera; - shows all cameras
webclient=# select "name" from "user" where id=17; - shows name for user with ID 17
webclient=# update "user" set name='ABC' where id=17;- changes name for user with ID 17