With the following relations:

Producers(pid: integer, pname: string, address: string)

Movies(mid: integer, mname: string, category: string)

Theaters(pid: integer, mid: integer, price: real)

Write the following SQL queries:

1. Find the pid of producers who produce only Action movies.
2. Find the pid of producers who produce an Action movie and a Comedy movie.
3. Find the pid of producers who produce an Action movie or a Comedy movie.