What are the names of the phones available?
select name from phone
What about those available in Alberta?
select t3.name from phone_market as t1 join market as t2 on t1.market_id = t2.market_id join phone as t3 on t1.phone_id = t3.phone_id where t2.district = "Alberta"
Show the district as well.
select t3.name, t2.district from phone_market as t1 join market as t2 on t1.market_id = t2.market_id join phone as t3 on t1.phone_id = t3.phone_id where t2.district = "Alberta"
Remove the restriction of those in Alberta only, show all instead.
select t3.name, t2.district from phone_market as t1 join market as t2 on t1.market_id = t2.market_id join phone as t3 on t1.phone_id = t3.phone_id