'array-contains' 查询不适用于引用的 Firestore [英] Firestore where 'array-contains' query doesn't work with references

问题描述

我有一个带有成员数组的聊天"集合，其中包含参与聊天的用户.问题是我想获得当前用户参与的所有聊天记录.

I have a collection 'chats' with a members array which contains users participating in the chat. The problem is I want to get all chats where the current user is participating.

我用这个查询来做到这一点:

I do this with this query:

getUserChats(): Observable<Chat[]> {
    return this.auth.currUser
      .pipe(
        take(1),
        switchMap(user => this.afs
            .collection('chats', ref => ref.where('members', 'array-contains', `/users/${user.uid}`))
            .snapshotChanges()
            .pipe(
              map(actions => {
                return actions.map(action => {
                  const data = action.payload.doc.data() as Chat;
                  const id = action.payload.doc.id;
                  return {id, ...data};
                });
              })
            ) as Observable<Chat[]>
        )
      );
  }

这适用于字符串，但不适用于引用.我怎样才能让它在参考文献上工作?

This works well for strings, but doesn't work with References. How can I also make it work on References?

绿色有效红色无效

绿色:字符串红色:参考

Green: String Red: Reference

推荐答案

@Alex Mamo 回答是对的，你需要一个 DocumentReference.

@Alex Mamo answer is right, you need a DocumentReference.

注意:您不能自己创建一个！

你必须通过查询 firebase 来获取引用！

You have to get the reference by querying firebase!

代码:

return this.auth.currUser
      .pipe(
        take(1),
        switchMap(user => this.afs
            .collection('chats', ref => ref.where('members', 'array-contains', this.afs
              .collection('users')
              .doc<User>(user.uid)
              .ref))
            .snapshotChanges()
            .pipe(
              map(actions => {
                return actions.map(action => {
                  const data = action.payload.doc.data() as Chat;
                  const id = action.payload.doc.id;
                  return {id, ...data};
                });
              })
            ) as Observable<Chat[]>
        )
      );

关键部分是价值"部分，即:

The crucial part is the 'value' part which is:

this.afs
              .collection('users')
              .doc<User>(user.uid)
              .ref

您查询并THEN获得带有 .ref 的引用！

You query and THEN get the reference with .ref!

就是这样！这就是您查询 DocumentReference 的方式！

That's it! That's how you query for a DocumentReference!

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