Count missing values
Which column of fortune500 has the most missing values? To find out, you'll need to check each column individually, although here we'll check just two: ticker and industry.
Course Note: While you're unlikely to encounter this issue during this exercise, note that if you run a query that takes more than a few seconds to execute, your session may expire or you may be disconnected from the server. You will not have this issue with any of the exercise solutions, so if your session expires or disconnects, there's an error with your query.
Questo esercizio fa parte del corso
Exploratory Data Analysis in SQL
Esercizio pratico interattivo
Prova a risolvere questo esercizio completando il codice di esempio.
-- Count the number of null values in the ticker column
SELECT count(*) - ___(___) AS ___
FROM ___;