Show me the number of regions affected for each storm.
select t1.name, count(*) from storm as t1 join affected_region as t2 on t1.storm_id = t2.storm_id group by t1.storm_id;
How about the number of storms for each region?
select t1.region_name, count(*) from region as t1 join affected_region as t2 on t1.region_id = t2.region_id group by t1.region_id;
Show the region name with at least two storms.
select t1.region_name from region as t1 join affected_region as t2 on t1.region_id = t2.region_id group by t1.region_id having count(*) >= 2;