CODEWITHSUNDEEP
phpfirebasegoogle-cloud-firestore
Lisio
Lisio

Reputation: 1601

Firestore: do I really need to check document existance for query results?

Firestore documentation recommends checking document for existance. What is the case for document to not exist if it was queried from the database?

$citiesRef = $db->collection('cities');
$query = $citiesRef->where('capital', '=', true);
$documents = $query->documents();
foreach ($documents as $document) {
    if ($document->exists()) {
        printf('Document data for document %s:' . PHP_EOL, $document->id());
        print_r($document->data());
        printf(PHP_EOL);
    } else {
        printf('Document %s does not exist!' . PHP_EOL, $snapshot->id());
    }
}

Upvotes: 1

Views: 164

Answers (2)

jeromegamez
jeromegamez

Reputation: 3551

It's true that all documents returned by a query do exist. The checks for existence are useful when you get a document directly.

$collection->document('anything') will always return a document reference, whether the document exists or not, so you can use exists() to determine how you want to proceed with that document.

Upvotes: 3

Mattias Martens
Mattias Martens

Reputation: 1657

There is no case for a document not to exist if it appeared as the result of iterating over an existing snapshot (citing Creating Empty Documents in Firestore).

I suspect this is an oversight in the documentation. $db->collection('cities') is an example of something that actually could be non-existent (in theory), although the example code does not check that.

Upvotes: 1

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