如何在Firestore中加入多个文档？

debugcn 发表于 Dev

拉斐尔·莫拉（Rafael Moura）

我有一个具有以下结构的Firestore数据库：

使用者
- [uid]
  - 名称：“用户一个”
艺术家
- [uid]
  - 风格：'流行睾丸'
  - user_uid：[uid]

为我服务

constructor(private afu: AngularFireAuth, private afs: AngularFirestore, private storage: AngularFireStorage) { 
   this.usersCollection = afs.collection<User>('users');
   this.users = this.usersCollection.valueChanges();
}

getUsers() {
   return this.users = this.usersCollection.snapshotChanges()
     .pipe(map(changes => {
       return changes.map(action => {
         const data = action.payload.doc.data() as User;
         return data
       });
     }));
 }

用户和艺术家之间如何加入？

本·布拉德肖

使用combineLatest是一个很好的方法。由于用户上不存在user_uid，因此我将idField作为user_uid添加到了用户。首先查看代码，然后阅读以下内容以获取解释。

    import { Component, OnInit } from '@angular/core';
    import { AngularFirestore } from '@angular/fire/firestore';
    import { Observable, combineLatest } from 'rxjs';
    interface User {
      name: string;
      user_uid: string;
    }
    interface Artist {
      style: string;
      user_uid: string;
    }
    interface Joined {
      user_uid: string;
      name: string;
      style: string;
    }
    @Component({
      selector: 'test',
      templateUrl: './test.component.html',
      styleUrls: ['./test.component.scss']
    })
    export class TestComponent implements OnInit {
    
      users$: Observable<User[]>;
      artists$: Observable<Artist[]>;
      joined$: Observable<Joined[]>;
      
      constructor(private afs: AngularFirestore){}
    
      ngOnInit(){
        this.users$ = this.afs.collection<User>('users').valueChanges({idField: 'user_uid'});
        this.artists$ = this.afs.collection<Artist>('artists').valueChanges();
        this.joined$ = combineLatest(this.users$, this.artists$, (users, artists) => {
            const joinedAsMap: Map<string, Joined> = new Map(artists.map(oneArtist =>  [oneArtist.user_uid, { ...{name: null} , ...oneArtist}]));
            users.forEach(one => joinedAsMap.set(one.user_uid , {...{name: one.name}, ...joinedAsMap.get(one.user_uid) } ));
            const joined: Joined[] = Array.from(joinedAsMap.values());
            return joined;
        });
      }
    }