> Then query it like so:
SELECT DISTINCT pokemon, special_attack
FROM pokemon as p
WHERE
p.special_attack > 120
AND EXISTS (
SELECT 1
FROM pokemon_moves as pm
WHERE p.pokemon_name = pm.pokemon_name AND move = 'freezedry'
)
AND EXISTS (
SELECT 1
FROM pokemon_types as pt
WHERE p.pokemon_name = pt.pokemon_name AND type = 'ice'
);
Hmm. I wonder if this SELECT DISTINCT pokemon, special_attack
FROM pokemon as p
NATURAL JOIN pokemon_moves as pm
NATURAL JOIN pokemon_types as pt
WHERE
p.special_attack > 120 AND
pm.move = 'freezedry' AND
pt.type = 'ice'
;
would work instead.
It would, but it forces the requirement of DISTINCT. With the original, if there were declared PKs (pokemon_name is fine for the main table, with a composite for others), the semi-join (EXISTS) would eliminate the need for DISTINCT entirely.
I think. Doing this in my head, but you could verify it trivially with SQLite or any other RDBMS.