Answers for "show all user of system mysql"

postgresql print sessions using the database

select pid as process_id, 
       usename as username, 
       datname as database_name, 
       client_addr as client_address, 
       application_name,
       backend_start,
       state,
       state_change
from pg_stat_activity;

database get 10 user aleatory

SELECT 
    t.customerNumber, t.customerName
FROM
    customers AS t
ORDER BY RAND()
LIMIT 5;