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()
.
This exercise is part of the course
Cleaning Data in SQL Server Databases
Exercise instructions
- Replace the missing values for
airport_city
column with the'Unknown'
string. - Replace the missing values for
airport_state
column with the'Unknown'
string.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
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