EXCEPT
EXCEPT does the opposite of INTERSECT. It is used to check if data, present in one table, is absent in another.
You want to know which countries have no recorded earthquakes. You can get this information by comparing the Nations table with the Earthquakes table.
Diese Übung ist Teil des Kurses
Improving Query Performance in SQL Server
Anleitung zur Übung
- Add the country code column from the
Nationstable. - Add the operator that compares the two queries.
- Add the table with country codes to the right query.
Interaktive Übung
Versuche dich an dieser Übung, indem du diesen Beispielcode vervollständigst.
SELECT ___ -- Add the country code column
FROM Nations
___ -- Add the operator to compare the two queries
SELECT Country
FROM ___; -- Table with country codes