Решение к #Задача6:

SELECT lower(e.last_name || ' ' || e.first_name) AS lower,
       upper(e.last_name || ' ' || e.first_name) AS upper,
       initcap(e.last_name || ' ' || e.first_name) AS initcap
  FROM employee e
 ORDER BY e.last_name, e.first_name

Решение в Postgresql

#задача