您可以通过查询特定的文档ID来实现:

You can achieve this by querying specific document id:

firestore.collection(collectionName).doc(documentId).valueChanges()
.subscribe(singleDoc =>{
console.log(singleDoc)
});

对您来说查询如下:

firestore.collection('123').doc('news1').valueChanges()
.subscribe(news1=>{
console.log(news1)
});