Here's a preview from my zine, Become a SELECT Star!! If you want to see more comics like this, sign up for my saturday comics newsletter or browse more comics!
read the transcript!
Conceptually, every step (like “WHERE”) of a query transforms its input, like this:
cats
owner: 1 name: daisy
owner: 1 name: dragonsnap
owner: 3 name: buttercup
owner: 4 name: rose
WHERE owner = 1
owner: 1 name: daisy
owner: 1 name: dragonsnap
The query’s steps don’t happen in the order they’re written:
how the query’ is written
SELECT…
FROM + JOIN
WHERE …
GROUP BY …
HAVING …
ORDER BY…
LIMIT…
how you should think about it:
FROM + JOIN
↓
WHERE
↓
GROUP BY
↓
HAVING
↓
SELECT
↓
ORDER BY
↓
LIMIT
(In reality query execution is much more complicated than this. There are a lot of optimizations.)
Saturday Morning Comics!
Want another comic like this in your email every Saturday? Sign up here!
