N+1 Fetch (ARCH9050)

Key swift.orm.n-plus-one-query · Severity warning · Category orm

Flags Core Data / Realm / GRDB fetches (context.fetch, realm.objects, db.read) inside a loop - one query per iteration.

Incorrect

for id in ids {
    let order = try context.fetch(request(for: id)).first
}

Correct

let request = Order.fetchRequest()
request.predicate = NSPredicate(format: "id IN %@", ids)
let orders = try context.fetch(request)

Fix

Fetch the set with one predicate before the loop.