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The very basics
Infinite looping
Processing trees with recursive CTEs
Processing graphs with recursive CTEs


Quite impressive, right? We'll now help you construct the query step-by-step so that you understand how it works.


In the first step, we'll show information about the boss. This is the only person in the table that has a NULL superior_id. For that person, show the id, first_name, last_name, superior_id, and a column called path with 'Boss' inside.

Stuck? Here's a hint!

Remember that you can check whether a value is NULL using:

WHERE column_name IS NULL