以下示例演示如何刪除文檔、字段和集合。
刪除文件
要刪除文檔,請使用delete()
方法:
Web version 9
import { doc, deleteDoc } from "firebase/firestore"; await deleteDoc(doc(db, "cities", "DC"));
Web version 8
db.collection("cities").doc("DC").delete().then(() => { console.log("Document successfully deleted!"); }).catch((error) => { console.error("Error removing document: ", error); });
迅速
db.collection("cities").document("DC").delete() { err in if let err = err { print("Error removing document: \(err)") } else { print("Document successfully removed!") } }
Objective-C
[[[self.db collectionWithPath:@"cities"] documentWithPath:@"DC"] deleteDocumentWithCompletion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error removing document: %@", error); } else { NSLog(@"Document successfully removed!"); } }];
Java
db.collection("cities").document("DC") .delete() .addOnSuccessListener(new OnSuccessListener<Void>() { @Override public void onSuccess(Void aVoid) { Log.d(TAG, "DocumentSnapshot successfully deleted!"); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Error deleting document", e); } });
Kotlin+KTX
db.collection("cities").document("DC") .delete() .addOnSuccessListener { Log.d(TAG, "DocumentSnapshot successfully deleted!") } .addOnFailureListener { e -> Log.w(TAG, "Error deleting document", e) }
Dart
db.collection("cities").doc("DC").delete().then( (doc) => print("Document deleted"), onError: (e) => print("Error updating document $e"), );
爪哇
Python
Python
C++
db->Collection("cities").Document("DC").Delete().OnCompletion( [](const Future<void>& future) { if (future.error() == Error::kErrorOk) { std::cout << "DocumentSnapshot successfully deleted!" << std::endl; } else { std::cout << "Error deleting document: " << future.error_message() << std::endl; } });
節點.js
去
PHP
$db->collection('samples/php/cities')->document('DC')->delete();
統一
DocumentReference cityRef = db.Collection("cities").Document("DC"); cityRef.DeleteAsync();
C#
DocumentReference cityRef = db.Collection("cities").Document("DC"); await cityRef.DeleteAsync();
紅寶石
刪除文檔時,Cloud Firestore 不會自動刪除其子集合中的文檔。您仍然可以通過引用訪問子集合文檔。例如,即使您刪除了位於/mycoll/mydoc
的祖先文檔,您也可以訪問路徑/mycoll/mydoc/mysubcoll/mysubdoc
中的文檔。
不存在的祖先文檔出現在控制台中,但它們不會出現在查詢結果和快照中。
如果要刪除文檔及其子集合中的所有文檔,則必須手動執行此操作。有關詳細信息,請參閱刪除集合。
刪除字段
要從文檔中刪除特定字段,請在更新文檔時使用FieldValue.delete()
方法:
Web version 9
import { doc, updateDoc, deleteField } from "firebase/firestore"; const cityRef = doc(db, 'cities', 'BJ'); // Remove the 'capital' field from the document await updateDoc(cityRef, { capital: deleteField() });
Web version 8
var cityRef = db.collection('cities').doc('BJ'); // Remove the 'capital' field from the document var removeCapital = cityRef.update({ capital: firebase.firestore.FieldValue.delete() });
迅速
db.collection("cities").document("BJ").updateData([ "capital": FieldValue.delete(), ]) { err in if let err = err { print("Error updating document: \(err)") } else { print("Document successfully updated") } }
Objective-C
[[[self.db collectionWithPath:@"cities"] documentWithPath:@"BJ"] updateData:@{ @"capital": [FIRFieldValue fieldValueForDelete] } completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error updating document: %@", error); } else { NSLog(@"Document successfully updated"); } }];
Java
DocumentReference docRef = db.collection("cities").document("BJ"); // Remove the 'capital' field from the document Map<String,Object> updates = new HashMap<>(); updates.put("capital", FieldValue.delete()); docRef.update(updates).addOnCompleteListener(new OnCompleteListener<Void>() { // ... // ...
Kotlin+KTX
val docRef = db.collection("cities").document("BJ") // Remove the 'capital' field from the document val updates = hashMapOf<String, Any>( "capital" to FieldValue.delete() ) docRef.update(updates).addOnCompleteListener { }
Dart
final docRef = db.collection("cities").doc("BJ"); // Remove the 'capital' field from the document final updates = <String, dynamic>{ "capital": FieldValue.delete(), }; docRef.update(updates);
爪哇
Python
Python
C++
DocumentReference doc_ref = db->Collection("cities").Document("BJ"); doc_ref.Update({{"capital", FieldValue::Delete()}}) .OnCompletion([](const Future<void>& future) { /*...*/ });
節點.js
去
PHP
$cityRef = $db->collection('samples/php/cities')->document('BJ'); $cityRef->update([ ['path' => 'capital', 'value' => FieldValue::deleteField()] ]);
統一
DocumentReference cityRef = db.Collection("cities").Document("BJ"); Dictionary<string, object> updates = new Dictionary<string, object> { { "Capital", FieldValue.Delete } };
C#
DocumentReference cityRef = db.Collection("cities").Document("BJ"); Dictionary<string, object> updates = new Dictionary<string, object> { { "Capital", FieldValue.Delete } }; await cityRef.UpdateAsync(updates);
紅寶石
刪除收藏
要刪除 Cloud Firestore 中的整個集合或子集合,請檢索集合或子集合中的所有文檔並將其刪除。如果您有較大的集合,您可能希望以較小的批次刪除文檔以避免內存不足錯誤。重複該過程,直到您刪除整個集合或子集合。
刪除一個集合需要協調無數個單獨的刪除請求。如果您需要刪除整個集合,請僅從受信任的服務器環境中執行此操作。雖然可以從移動/Web 客戶端刪除集合,但這樣做會對安全性和性能產生負面影響。
下面的代碼片段有些簡化,不涉及錯誤處理、安全性、刪除子集合或最大化性能。要了解有關在生產中刪除集合的一種推薦方法的更多信息,請參閱刪除集合和子集合。
網絡
// Deleting collections from a Web client is not recommended.
迅速
// Deleting collections from an Apple client is not recommended.
Objective-C
// Deleting collections from an Apple client is not recommended.
Java
// Deleting collections from an Android client is not recommended.
Kotlin+KTX
// Deleting collections from an Android client is not recommended.
Dart
不建議從客戶端刪除集合。
爪哇
Python
Python
C++
// This is not supported. Delete data using CLI as discussed below.
節點.js
去
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(); } }
統一
// This is not supported. Delete data using CLI as discussed below.
C#
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."); }
紅寶石
使用 Firebase CLI 刪除數據
您還可以使用Firebase CLI刪除文檔和集合。使用以下命令刪除數據:
firebase firestore:delete [options] <<path>>
使用控制台刪除數據
您可以從控制台的 Cloud Firestore 頁面中刪除文檔和集合。從控制台刪除文檔會刪除該文檔中的所有嵌套數據,包括任何子集合。