SQL Fundamentals - Assessment - Nested subqueries

Q&A
#1

Screen Link: https://app.dataquest.io/m/2000603/nested-and-correlated-subqueries-assessment/5/question-5

My code so far:

 SELECT at.title
   FROM (SELECT *
           FROM track t
           JOIN album a
             ON t.album_id = a.album_id) AS at
  WHERE NOT EXIST (SELECT *
                     FROM invoice_line i
                    WHERE at.track_id = i.track_id);

What I expected to happen:

A query that display all albums that have tracks that have never been sold.

What actually happened:

OperationalError: near "SELECT": syntax error

An alternative query I tried that gives the same error:

 SELECT title
   FROM album a
  WHERE album_id IN (SELECT album_id
                       FROM track t
                      WHERE NOT EXIST (SELECT *
                                         FROM invoice_line i
                                        WHERE t.track_id = i.track_id));

Can you please help me out with this, explain the logic behind the code? What am I doing wrong? This exercise is driving me crazy. The lack of feedback and solution at the end got me stuck in a endless loop of trial and error.

#2

Ok so the correct clause would be WHERE NOT EXISTS.

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