1. Find all pizzas eaten by at least one female over the age of 20.
\project_{pizza}(
(\project_{name} // nombre de todas las female
\select_{gender='female' and age > 20}
Person
)
\join Eats
)
2.Find the names of all females who eat at least one pizza served by Straw Hat.
(Note: The pizza need not be eaten at Straw Hat.)
\project_{name}(
(\project_{name} // nombre de todas las female
\select_{gender='female'}
Person
)
\join
(
( Eats)
\join
( \select_{pizzeria='Straw Hat'} Serves)
)
)
3. Find all pizzerias that serve at least one pizza for less than $10
that either Amy or Fay (or both) eat.
\project_{pizzeria} (
( \select_{price < 10} Serves )
\join
( \select_{name='Amy' or 'Fay'} Eats )
)
