As the speaker in the aforementioned talk, this seems as good a place as any to apologize for all of the mistakes.

I usually test all of the code in my slides, but I made a number of changes at the last minute and didn’t go through my usual cross checks. Rest assured, I won’t be making that mistake again

I’m very grateful to @idi527 for pointing out the errors. I’m going to take some time to go through everything and update the slides. I’ll also talk to the conf organizers to see what can be done about updating the video.

Again, my apologies. Lesson learned, the hard way (as usual…)

Great talk - there were some typos…

at https://youtu.be/YQxopjai0CU?t=697

this won’t work

albums.tracks

something like this, however, will

for album <- albums, do: album.tracks

at https://youtu.be/YQxopjai0CU?t=892

a typo in

def with_tracks_longer_than(name, duration) do

should be

def with_tracks_longer_than(query, duration) do

at https://youtu.be/YQxopjai0CU?t=1147

Repo.transaction do
  ...
end

is not valid, it’s does not accept ast, but a function
should be

Repo.transaction(fn ->
  ...
end)

at https://youtu.be/YQxopjai0CU?t=1260

in the case of an error, the returned tuple will have four entries

{:error, atom, any, %{optional(atom) => any}}

the code on the slides should be

case result do
  …
  {:error, :album, album_changeset, _changes} -> …
  {:error, :user, user_changeset, _changes} -> …
end

at https://youtu.be/YQxopjai0CU?t=1288

missed do keyword and the argument to the function
the code should probably be

def check_user_progress(%{user: user}) do
  ...
end

at https://youtu.be/YQxopjai0CU?t=1435

Repo.all/1 will return a list for both queries
the code for the first one should be

Repo.all(q1)
=> [%MusinDb.Artist{...}]

Any mistakes aside, I enjoyed the talk