Filling missing values using ISNULL()
In the previous exercise, you practiced how to exclude and select the rows with NULL values. However, depending on the business assumptions behind your data, you may want to select all the rows with NULL values, but replacing these NULL values with another value. You can do it using ISNULL().
Now, you want to replace all the NULL values for the airport_city and airport_state columns with the word 'Unknown', using ISNULL().
Questo esercizio fa parte del corso
Cleaning Data in SQL Server Databases
Istruzioni dell'esercizio
- Replace the missing values for
airport_citycolumn with the'Unknown'string. - Replace the missing values for
airport_statecolumn with the'Unknown'string.
Esercizio pratico interattivo
Prova a risolvere questo esercizio completando il codice di esempio.
SELECT
airport_code,
airport_name,
-- Replace missing values for airport_city with 'Unknown'
___(___, '___') AS airport_city,
-- Replace missing values for airport_state with 'Unknown'
___(___, '___') AS airport_state
FROM airports