如何更新 Firestore 中陣列欄位中的單一項目？

Updating Single Item in an Array Field in Firestore

The FirebaseFirestore documentation describes ways to interact with array fields, including adding or removing elements. However, it lacks a method for directly updating an item inside the array.

For a document like:

{
 name: 'Foo',
 items: [
   {
     name: 'Bar',
     meta: {
        image: 'xyz.png',
        description: 'hello world'
     }
   },
   {
     name: 'Rawr',
     meta: {
        image: 'abc.png',
        description: 'hello tom'
     }
   }
 ]
}

To modify a nested property like items[0].meta.description, the following approach won't work:

const key = `items.${this.state.index}.meta.description`;
const property = `hello bar`;

this.design.update({
  [key]: property
}).then(() => { console.log("done") 
}).catch(function(error) { 
   message.error(error.message); 
});

It removes all properties in the targeted array index and only keeps the description property.

Rewriting the entire object also isn't desirable:

const key = `items.${this.state.index}.meta`;
const property = e.target.value;
let meta = this.state.meta;
meta[e.target.id] = property;

this.design.update({
[key]: meta
}).then(() => {
  this.setState({
    [key]: meta
  }) 
}).catch(function(error) { 
  message.error(error.message); 
});

It converts the entire items array into an object.

Instead, read the array from the document, make changes in memory, and update the entire modified array field:

const docRef = firestore.collection('collection').doc('document');

docRef.get().then(doc => {
  const items = doc.data().items;

  items[0].meta.description = "hello bar";

  docRef.update({
    items: items
  });
});

This ensures only the intended property is updated in the array element.

以上是如何更新 Firestore 中陣列欄位中的單一項目？的詳細內容。更多資訊請關注PHP中文網其他相關文章！