Solutions - SQL Basics

1. Use

   select distinct residence from person;
   

2. Use

   select count(distinct residence) from person;
   

3. Use

   select * from person where name like '%oh%';
   

4. Use

   select * from flight where date < "2014-10-20";
   

5. Use

   select * from person where name in ('Philipp', 'Carlos') 
   

   and

   select * from person where name = 'Philipp' or name = 'Carlos'
   

6. Use

   select * from person where name = 'Philipp' and age > 50;
   

7. For all contracts use

   select count(*) from phone_contract;
   

and for the actives ones

select count(*) from phone_contract where status = 'active';

8. We get all combinations of names and phone numbers.

9. Use

   select person.name, person.age from person, phone_contract
   where person.name=phone_contract.name and status = 'active';
   

10. Use

    select p.name, phone_number from person p, phone_contract c where
    p.name = c.name and age > 30;
    

11. It returns name, age, residence and phone number for all people who have the same age as persons living in Paris.