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Firestore-Sammlung löschen

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Codebeispiel

C#

Richten Sie die Standardanmeldedaten für Anwendungen ein, um sich bei Firestore zu authentifizieren. Weitere Informationen finden Sie unter Authentifizierung für eine lokale Entwicklungsumgebung einrichten.

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.");
}

Go


import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/firestore"
	"google.golang.org/api/iterator"
)

func deleteCollection(w io.Writer, projectID, collectionName string,
	batchSize int) error {

	// Instantiate a client
	ctx := context.Background()
	client, err := firestore.NewClient(ctx, projectID)
	if err != nil {
		return err
	}

	col := client.Collection(collectionName)
	bulkwriter := client.BulkWriter(ctx)

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

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

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

		// If there are no documents to delete,
		// the process is over.
		if numDeleted == 0 {
			bulkwriter.End()
			break
		}

		bulkwriter.Flush()
	}
	fmt.Fprintf(w, "Deleted collection \"%s\"", collectionName)
	return nil
}

Java

/**
 * 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());
  }
}

Node.js

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);
  });
}

PHP

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();
    }
}

Python

def delete_collection(coll_ref, batch_size):
    if batch_size == 0:
        return

    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)

Ruby

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

Nächste Schritte

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