如何获取具有id的特定文档数据? | AngularFire 5.1.1 | Cloud Firestore |文件资料 [英] How to get particular document data with id ? | AngularFire 5.1.1 | Cloud Firestore | Documents
问题描述
我正在使用数据访问服务从Firebase Firestore获取数据.
I am using Data access service to get the data from firebase firestore.
如何使用snapshotChanges()方法获取具有ID的特定文档数据
How to use snapshotChanges()method for getting particular document data with id
getProduct(id: number): Observable<Product> {
this.productsDocuments = this.angularfirestore.doc<Product>('products/' + id);
this.product = this.productsDocuments.snapshotChanges().pipe(
map(changes => changes.map(a => {
const data = a.payload.doc.data() as Product;
const id = a.payload.doc.id;
return { id, ...data };
}))
);
return this.product
我要this.product返回文档值和文档ID
I want this.product returns the document value and document id
谢谢！
推荐答案
文档只是对象{[field]: value}
集合是文档[document]的容器.
A document is simply an object {[field]: value}
and a collection is a container for documents [document].
您正在尝试获取单个文档/对象，但问题是您无法直接映射到该文档/对象.我认为您想获取整个集合，然后映射所有文档.
You are trying to get a single document/object and the problem is that you cannot map to it directly. I think that you want to get the entire collection, and then map over all of the documents.
getProduct(id: number): Observable<Product> {
const productsDocuments = this.db.doc<Product>('products/' + id);
return productsDocuments.snapshotChanges()
.pipe(
map(changes => {
const data = changes.payload.data();
const id = changes.payload.id;
return { id, ...data };
}))
}
getProduct(id: number): Observable<Product> {
const productsDocuments = this.db.doc<Product>('products/' + id);
return productsDocuments.snapshotChanges()
.pipe(
map(changes => {
const data = changes.payload.data();
const id = changes.payload.id;
return { id, ...data };
}))
}
用于收藏
getProduct(id: string): Observable<Product[]> {
const productsDocuments = this.db.collection<Product[]>('products');
return productsDocuments.snapshotChanges()
.pipe(
map(changes => changes.map(({ payload: { doc } }) => {
const data = doc.data();
const id = doc.id
return { id, ...data };
})),
map((products) => products.find(doc => doc.id === id)))
}
getProduct(id: string): Observable<Product[]> {
const productsDocuments = this.db.collection<Product[]>('products');
return productsDocuments.snapshotChanges()
.pipe(
map(changes => changes.map(({ payload: { doc } }) => {
const data = doc.data();
const id = doc.id
return { id, ...data };
})),
map((products) => products.find(doc => doc.id === id)))
}
这篇关于如何获取具有id的特定文档数据? | AngularFire 5.1.1 | Cloud Firestore |文件资料的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
