Exercise

Diagnosing problems using anti-join

Another powerful join in SQL is the anti-join. It is particularly useful in identifying which records are causing an incorrect number of records to appear in join queries.

You will also see another example of a subquery here, as you saw in the first exercise on semi-joins. Your goal is to identify the currencies used in Oceanian countries!

Instructions 1/3

XP

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Begin by determining the number of countries in countries that are listed in Oceania using SELECT, FROM, and WHERE.

Take Hint (-10 XP)