Removing missing values
It is common to find missing values in your data. SQL Server represents missing values with NULL.
IS NULL and IS NOT NULL enable you to select or remove the rows where missing values are represented by NULL.
The airport_city column of the airports table has some NULL values. Try to find them!
Este exercício faz parte do curso
Cleaning Data in SQL Server Databases
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
SELECT *
-- Select the appropriate table
FROM ___
-- Exclude the rows where airport_city is NULL
WHERE ___ ___ ___ ___