Using different joins to explore athletes' regions

You probably know about the Olympians from your country. Many Russians watch figure skating. Kenyans have a strong presence in running events. Canadians dominate hockey. Do these trends hold true across regions? Do all European countries have figure skating Olympians? Do all North Americans have Olympic-level hockey teams?

See which European countries sent figure skating competitors to the 2014 Winter Olympics. The athletes table is already filtered to figure skating athletes, and the regions table is filtered to European countries. Use the different join types and compare the results.

1
Use regions, athletes, and a LEFT JOIN to keep all the regions, even those with no competing athletes.
2
Now use a RIGHT JOIN to keep all the regions, even those with no competing athletes.
3
Use an INNER JOIN to find only countries with competing athletes.

Exercise

Using different joins to explore athletes' regions

Instructions 1/3