How many counties with location on the east?
select count(*) from county_public_safety where location = "East"
How about the number of counties with location on the west?
select count(*) from county_public_safety where location = "West"
Please show the police forces in counties with location on the east.
select police_force from county_public_safety where location = "East"
How about the police forces shared by counties with location on the east and west?
select police_force from county_public_safety where location = "East" intersect select police_force from county_public_safety where location = "West"