That would be overkill, however, because embedding IN clauses within IN
clauses only makes the query harder to read.We did so in the previous example
to show you that you can do it. It’s worth restating, though, that just
because you can do something doesn’t mean you should! We think you’ll
agree that it’s easier to see what’s going on by using a single IN predicate and
a more complex JOIN in the subquery. Here’s another solution using this
technique.