Javascript 安萨科。通过提供带有merge:true的SetOptions，可以将这些调用配置为执行粒度合并，而不是覆盖目标文档的全部内容

你可以用这个

const yourNewArray = [{who: "first@test.com", when:timestamp}
{who: "another@test.com", when:timestamp}]    


collectionRef.doc(docId).set(
  {
    proprietary: "jhon",
    sharedWith: firebase.firestore.FieldValue.arrayUnion(...yourNewArray),
  },
  { merge: true },
);

---

希望这有帮助：）

这太令人沮丧了……但谢谢你让我知道我没有发疯。这是一个很大的缺点，谷歌必须尽快解决。@Dougalante的回答表明这已经解决了。使用

arrayUnion

方法。是否有任何方法从数组更新特定索引？如何将此数组更新功能与“react native firebase”一起使用？（我在react native firebase的官方文档中找不到这一点）@ArturCarvalho否，此视频中解释了为什么需要在客户端执行此操作，请使用“从'firebase/app'导入*作为firebase”；然后使用“firebase.firestore.FieldValue.arrayUnion（新元素）”如果有一种方法可以使用特定id更新数组中的项，那就太好了。就像arrayUnion，但有一个merge:true。此时需要2个操作来删除数组项，然后使用新数据再次添加它。在if语句中，您应该将其更改为此，因为您缺少

documentReference

add

userRef

，如图所示：

transaction.set（userRef，{bookings:[booking]}）

@nifCody，这确实会在现有数组“regions”中添加一个新的字符串元素“greater_virginia”。我已经成功地测试了它，而且绝对没有添加“object”。这与“推新记录”的问题是一致的。请解释你的答案。事实上，请阅读嘿，你找到答案了吗？我仍然找不到答案。虽然这可能会回答问题，但如果可能的话，您应该在您的答案中包含此代码块如何回答问题的简短解释。这有助于提供上下文，并使你的答案对未来的读者更有用。@hoppeduppen但你是对的。我绝对接受批评，因为我没有为我的答案添加解释。我已经编辑了我的答案。希望它现在能帮上大忙。

// With SET
firebase.firestore()
.collection('proprietary')
.doc(docID)
.set(
  { sharedWith: [{ who: "third@test.com", when: new Date() }] },
  { merge: true }
)

// With UPDATE
firebase.firestore()
.collection('proprietary')
.doc(docID)
.update({ sharedWith: [{ who: "third@test.com", when: new Date() }] })

firebase.firestore()
.collection('proprietary')
.doc(docID)
.set(
  { sharedWith: [{ who: "third@test.com", when: new Date() }] },
  { merge: true }
)

firebase.firestore()
  .collection('proprietary')
  .doc(docID)
  .collection('sharedWith')
  .add({ who: "third@test.com", when: new Date() })

  // say you have have the following object and 
  // database structure as you mentioned in your post
  data = { who: "third@test.com", when: new Date() };

  ...othercode


  addSharedWith(data) {

    const postDocRef = this.afs.collection('posts').doc('docID');

    postDocRef.subscribe( post => {

      // Grab the existing sharedWith Array
      // If post.sharedWith doesn`t exsit initiated with empty array
      const foo = { 'sharedWith' : post.sharedWith || []};

      // Grab the existing sharedWith Array
      foo['sharedWith'].push(data);

      // pass updated to fireStore
      postsDocRef.update(foo);
      // using .set() will overwrite everything
      // .update will only update existing values, 
      // so we initiated sharedWith with empty array
    });
 }  

    const booking = { some: "data" };
    const userRef = this.db.collection("users").doc(userId);

    this.db.runTransaction(transaction => {
        // This code may get re-run multiple times if there are conflicts.
        return transaction.get(userRef).then(doc => {
            if (!doc.data().bookings) {
                transaction.set({
                    bookings: [booking]
                });
            } else {
                const bookings = doc.data().bookings;
                bookings.push(booking);
                transaction.update(userRef, { bookings: bookings });
            }
        });
    }).then(function () {
        console.log("Transaction successfully committed!");
    }).catch(function (error) {
        console.log("Transaction failed: ", error);
    });

proprietary: "John Doe"
sharedWith:{
  whoEmail1: {when: timestamp},
  whoEmail2: {when: timestamp}
}

var whoEmail = 'first@test.com';

var sharedObject = {};
sharedObject['sharedWith.' + whoEmail + '.when'] = new Date();
sharedObject['merge'] = true;

firebase.firestore()
.collection('proprietary')
.doc(docID)
.update(sharedObject);

proprietary: "John Doe"(a document)

things(collection of John's things documents)

thingsSharedWithOthers(collection of John's things being shared with others):
[thingId]:
    {who: "first@test.com", when:timestamp}
    {who: "another@test.com", when:timestamp}

then set thingsSharedWithOthers

firebase.firestore()
.collection('thingsSharedWithOthers')
.set(
{ [thingId]:{ who: "third@test.com", when: new Date() } },
{ merge: true }
)

List<String> list = java.util.Arrays.asList("A", "B");
Object[] fieldsToUpdate = list.toArray();
DocumentReference docRef = getCollection().document("docId");
docRef.update(fieldName, FieldValue.arrayUnion(fieldsToUpdate));

addToCart(docId: string, prodId: string): Promise<void> {
    return this.baseAngularFirestore.collection('carts').doc(docId).update({
        products:
        firestore.FieldValue.arrayUnion({
            productId: prodId,
            qty: 1
        }),
    });
}

    var documentRef = db.collection("Your collection name").doc("Your doc name")

    documentRef.update({
yourArrayName: firebase.firestore.FieldValue.arrayUnion("The Value you want to enter")});

const yourNewArray = [{who: "first@test.com", when:timestamp}
{who: "another@test.com", when:timestamp}]    


collectionRef.doc(docId).set(
  {
    proprietary: "jhon",
    sharedWith: firebase.firestore.FieldValue.arrayUnion(...yourNewArray),
  },
  { merge: true },
);