-- https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/CAST.html
SELECT e.last_name,
       CAST(MULTISET(SELECT p.project_name
                       FROM projects p 
                       WHERE p.employee_id = e.employee_id
                       ORDER BY p.project_name)
       AS project_table_typ)
  FROM emps_short e
  ORDER BY e.last_name;