Final answer:
The ORDER BY keyword can be used to override the order in which NULL values appear in the results of a query.
Step-by-step explanation:
The order in which NULL values appear in the results can be overridden by using the keyword ORDER BY. The ORDER BY clause is used to sort the result set of a query based on one or more columns. By specifying the desired column in the ORDER BY clause, you can control the order in which NULL values are displayed.