CREATE TABLE people (name varchar(100), employer int, age int, experience int, salary int, commission int, education varchar(50));
CREATE TABLE companies (corpname varchar(50), location varchar(2), earnings int, president varchar(100), business varchar(50));
CREATE TABLE schools (schoolname varchar(50), level varchar(50));

# Q1
#SELECT name, experience FROM people WHERE experience >= 10;
SELECT people.name, people.experience FROM people WHERE people.experience >= 10;

# Q2
#SELECT name, experience FROM people WHERE experience >= 20 AND age <= 65;
SELECT people.name, people.experience FROM people WHERE people.experience >= 20 AND people.age <= 65;

# Q3
SELECT p.name, c.corpname, c.location, c.president FROM people AS p, companies AS c WHERE p.experience >= 10 AND p.employer = c.corpname AND c.location <> 'AK' AND c.earnings > 500000;

# Q4
SELECT p.name, c.corpname, c.location FROM people AS p, companies AS c WHERE p.experience >= 20 AND p.age <= 65 AND p.employer = c.corpname AND c.location = 'NY' AND c.earnings > 500000;

# Q5
SELECT p.name, s.schoolname FROM people AS p, companies AS c, schools AS s WHERE p.experience >= 20 AND p.age <= 65 AND p.employer = c.corpname AND c.location = 'NY' AND c.earnings > 500000 AND p.education = s.schoolname AND s.level = 'university';

# Q6
# Need proper support of table aliases
# SELECT p.name, c.corpname, c.location FROM people AS p, companies AS c, companies AS c1 WHERE p.experience >= 20 AND p.age <= 65 AND p.employer = c.corpname AND ( c.location = 'NY' OR c.location = 'CA' ) AND c.earnings > 500000 AND p.name = c1.president AND c1.president = 'Smith' AND c1.business = 'manufacturing';