Exercise: 70
Get the battles in which at least three ships from the same country took part.
The database consists of the following relations:
Classes(class, type, country, numGuns, bore, displacement)
Ships(name, class, launched)
Battles(name, date)
Outcomes(ship, battle, result)
Notes: 4) A ship found in the Outcomes table but not in the Ships table is still considered in the database. This is true even if it is sunk.