Challenge 1 / 2

You build a page that lists 50 StarshipPart records and shows each part’s starship name. You write this inside a loop: $part->getStarship()->getName(). After the Doctrine upgrade, what’s the sneaky performance problem you might run into, and what’s a good fix?

The issue is that native lazy objects disable lazy-loading in loops, so $part->getStarship()->getName() won’t cause extra queries; no fix is needed besides upgrading Doctrine.

It will crash because native lazy objects don’t allow calling methods like getName() inside a loop. Fix it by making the entities non-final.

You can trigger 1 query to load the parts, then up to 50 extra queries (one per starship) when you call getName(). Fix it by fetching the starships up front with a join (or addSelect) so Doctrine grabs everything in fewer queries.

Doctrine will always be smart and automatically merge all those lazy loads into one extra query. No fix needed—lazy objects always prevent extra queries.

Rewatch the video