1. Aprende
    2. /
  2. Cursos
    3. /
  3. Improving Query Performance in PostgreSQL
Connected

Ejercicio

Filtering in the join, where, and select

Looking at all the countries with gross domestic product (GDP) data in 2014, the average GDP per capita was $19,342. For African countries, the average GDP per capita was $5,879.

Perhaps the African countries that sent athletes to the Olympics (Morocco, Togo, Zimbabwe) did not have the highest GDPs per capita in Africa but had higher GDPs than the average African GDP.

Test this theory. Find the per capita GDP for the African countries with athletes at the 2014 Winter Games.

Instrucciones

100 XP
  • The athletes' data is already limited to African competitors. Find the unique athletes from the athletes_wint table.
  • Use the JOIN to filter the athletes to only those with odemographic (GDP) data.
  • Use a year filter from the athletes_wint table to restrict results to only the 2014 athletes.