From the staff table, format each staff member's date of joining (doj) as a YYYY-MM string (four-digit year, a hyphen, then the two-digit month). Return the columns id, staff_fname, staff_lname, and the formatted value as join_month, sorted by join_month (ascending), then by staff_lname (ascending).
Database schema
primary keyforeign keyarrow points to the referenced columndrag to pan