Imputing missing values (I)

In the previous exercise, you looked at the non-missing values in the IncidentState column. But what if you want to replace the missing values with another value instead of omitting them? You can do this using the ISNULL() function. Here we replace all the missing values in the Shape column using the word 'Saucer':

SELECT  Shape, ISNULL(Shape, 'Saucer') AS Shape2
FROM Incidents

You can also use ISNULL() to replace values from a different column instead of a specified word.

Deze oefening maakt deel uit van de cursus

Intermediate SQL Server

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Oefeninstructies

Write a T-SQL query which only returns rows where IncidentState is missing.
Replace all the missing values in the IncidentState column with the values in the City column and name this new column Location.

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

-- Check the IncidentState column for missing values and replace them with the City column
SELECT IncidentState, ___ AS Location
FROM Incidents
-- Filter to only return missing values from IncidentState
WHERE ___ ___ ___

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