CloudFirestoreからデータを削除します

// asynchronously delete a document
ApiFuture<WriteResult> writeResult = db.collection("cities").document("DC").delete();
// ...
System.out.println("Update time : " + writeResult.get().getUpdateTime());
ManageDataSnippets.java

db.collection(u'cities').document(u'DC').delete()
snippets.py

await db.collection("cities").document("DC").delete()
snippets.py

const res = await db.collection('cities').doc('DC').delete();
index.js

_, err := client.Collection("cities").Doc("DC").Delete(ctx)
if err != nil {
	// Handle any errors in an appropriate way, such as returning them.
	log.Printf("An error has occurred: %s", err)
}
save.go

$db->collection('samples/php/cities')->document('DC')->delete();
data_delete_doc.php

DocumentReference cityRef = db.Collection("cities").Document("DC");
await cityRef.DeleteAsync();
Program.cs

city_ref = firestore.doc "#{collection_path}/DC"
city_ref.delete
delete_data.rb

DocumentReference docRef = db.collection("cities").document("BJ");
Map<String, Object> updates = new HashMap<>();
updates.put("capital", FieldValue.delete());
// Update and delete the "capital" field in the document
ApiFuture<WriteResult> writeResult = docRef.update(updates);
System.out.println("Update time : " + writeResult.get());
ManageDataSnippets.java

city_ref = db.collection(u'cities').document(u'BJ')
city_ref.update({
    u'capital': firestore.DELETE_FIELD
})
snippets.py

city_ref = db.collection("cities").document("BJ")
await city_ref.update({"capital": firestore.DELETE_FIELD})
snippets.py

// Create a document reference
const cityRef = db.collection('cities').doc('BJ');

// Remove the 'capital' field from the document
const res = await cityRef.update({
  capital: FieldValue.delete()
});
index.js

_, err := client.Collection("cities").Doc("BJ").Update(ctx, []firestore.Update{
	{
		Path:  "capital",
		Value: firestore.Delete,
	},
})
if err != nil {
	// Handle any errors in an appropriate way, such as returning them.
	log.Printf("An error has occurred: %s", err)
}
save.go

$cityRef = $db->collection('samples/php/cities')->document('BJ');
$cityRef->update([
    ['path' => 'capital', 'value' => FieldValue::deleteField()]
]);
data_delete_field.php

DocumentReference cityRef = db.Collection("cities").Document("BJ");
Dictionary<string, object> updates = new Dictionary<string, object>
{
    { "Capital", FieldValue.Delete }
};
await cityRef.UpdateAsync(updates);
Program.cs

city_ref = firestore.doc "#{collection_path}/BJ"
city_ref.update({ capital: firestore.field_delete })
delete_data.rb

/**
 * Delete a collection in batches to avoid out-of-memory errors. Batch size may be tuned based on
 * document size (atmost 1MB) and application requirements.
 */
void deleteCollection(CollectionReference collection, int batchSize) {
  try {
    // retrieve a small batch of documents to avoid out-of-memory errors
    ApiFuture<QuerySnapshot> future = collection.limit(batchSize).get();
    int deleted = 0;
    // future.get() blocks on document retrieval
    List<QueryDocumentSnapshot> documents = future.get().getDocuments();
    for (QueryDocumentSnapshot document : documents) {
      document.getReference().delete();
      ++deleted;
    }
    if (deleted >= batchSize) {
      // retrieve and delete another batch
      deleteCollection(collection, batchSize);
    }
  } catch (Exception e) {
    System.err.println("Error deleting collection : " + e.getMessage());
  }
}
ManageDataSnippets.java

def delete_collection(coll_ref, batch_size):
    docs = coll_ref.list_documents(page_size=batch_size)
    deleted = 0

    for doc in docs:
        print(f'Deleting doc {doc.id} => {doc.get().to_dict()}')
        doc.delete()
        deleted = deleted + 1

    if deleted >= batch_size:
        return delete_collection(coll_ref, batch_size)
snippets.py

async def delete_collection(coll_ref, batch_size):
    docs = coll_ref.limit(batch_size).stream()
    deleted = 0

    async for doc in docs:
        print(f"Deleting doc {doc.id} => {doc.to_dict()}")
        await doc.reference.delete()
        deleted = deleted + 1

    if deleted >= batch_size:
        return delete_collection(coll_ref, batch_size)
snippets.py

async function deleteCollection(db, collectionPath, batchSize) {
  const collectionRef = db.collection(collectionPath);
  const query = collectionRef.orderBy('__name__').limit(batchSize);

  return new Promise((resolve, reject) => {
    deleteQueryBatch(db, query, resolve).catch(reject);
  });
}

async function deleteQueryBatch(db, query, resolve) {
  const snapshot = await query.get();

  const batchSize = snapshot.size;
  if (batchSize === 0) {
    // When there are no documents left, we are done
    resolve();
    return;
  }

  // Delete documents in a batch
  const batch = db.batch();
  snapshot.docs.forEach((doc) => {
    batch.delete(doc.ref);
  });
  await batch.commit();

  // Recurse on the next process tick, to avoid
  // exploding the stack.
  process.nextTick(() => {
    deleteQueryBatch(db, query, resolve);
  });
}
index.js

func deleteCollection(ctx context.Context, client *firestore.Client,
	ref *firestore.CollectionRef, batchSize int) error {

	for {
		// Get a batch of documents
		iter := ref.Limit(batchSize).Documents(ctx)
		numDeleted := 0

		// Iterate through the documents, adding
		// a delete operation for each one to a
		// WriteBatch.
		batch := client.Batch()
		for {
			doc, err := iter.Next()
			if err == iterator.Done {
				break
			}
			if err != nil {
				return err
			}

			batch.Delete(doc.Ref)
			numDeleted++
		}

		// If there are no documents to delete,
		// the process is over.
		if numDeleted == 0 {
			return nil
		}

		_, err := batch.Commit(ctx)
		if err != nil {
			return err
		}
	}
}
save.go

function data_delete_collection(string $projectId, string $collectionName, int $batchSize)
{
    // Create the Cloud Firestore client
    $db = new FirestoreClient([
        'projectId' => $projectId,
    ]);
    $collectionReference = $db->collection($collectionName);
    $documents = $collectionReference->limit($batchSize)->documents();
    while (!$documents->isEmpty()) {
        foreach ($documents as $document) {
            printf('Deleting document %s' . PHP_EOL, $document->id());
            $document->reference()->delete();
        }
        $documents = $collectionReference->limit($batchSize)->documents();
    }
}
data_delete_collection.php

private static async Task DeleteCollection(CollectionReference collectionReference, int batchSize)
{
    QuerySnapshot snapshot = await collectionReference.Limit(batchSize).GetSnapshotAsync();
    IReadOnlyList<DocumentSnapshot> documents = snapshot.Documents;
    while (documents.Count > 0)
    {
        foreach (DocumentSnapshot document in documents)
        {
            Console.WriteLine("Deleting document {0}", document.Id);
            await document.Reference.DeleteAsync();
        }
        snapshot = await collectionReference.Limit(batchSize).GetSnapshotAsync();
        documents = snapshot.Documents;
    }
    Console.WriteLine("Finished deleting all documents from the collection.");
}
Program.cs

cities_ref = firestore.col collection_path
query      = cities_ref

query.get do |document_snapshot|
  puts "Deleting document #{document_snapshot.document_id}."
  document_ref = document_snapshot.ref
  document_ref.delete
end
delete_data.rb