NOT IN with IS NOT NULL
You want to know which country capitals have never been the closest city to recorded earthquakes. You decide to use NOT IN
to compare Capital
from the Nations
table, in the outer query, with NearestPop
, from the Earthquakes
table, in a sub-query.
Este exercício faz parte do curso
Improving Query Performance in SQL Server
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
SELECT WorldBankRegion,
CountryName,
___ -- Capital city name column
FROM Nations
WHERE Capital NOT IN
(SELECT ___ -- City name column
FROM Earthquakes);