SQL Database queries question:

Consider the following database which has the following relations:

Movies ( title, year, length, genre, studioName, producer_id )

Stars ( movieTitle, movieYear, starName )

MovieStar ( name, address, gender, birthdate )

MovieExec ( name, id, address, networth )

Studio ( name, address, president_id )

Where movie executives can be producers or studio presidents and they have unique id numbers. Assume that names of people are unique, there is one producer of each movie, and each studio has one president.

Express the following queries using SQL:

1. (a)Find the names of presidents of studios that released a movie in 2017.

(b)Find movies which star more than 10 movie stars.

(c) Find movie stars who only star in movies produced by Guillermo del Toro

(d)Find the titles of movies that have been used for two or more movies