javascript - firebase indexOn 用于子值

Question

我正在尝试使用 firebase 查询获取情绪等于 M1 的所有帖子，如下所示:

db.ref(`Recommendations`).orderByChild(`post/vote/moodTags/${idMood}/key`).equalTo(`${idMood}`).once('value').then(recs =>{
        //Número de recs con el mood
        let recsCount = recs.numChildren();
        console.log(`Número de recs encontradas --> ${recsCount}`);
        ...
    });

并且 firebase 控制台显示警告:

FIREBASE WARNING: Using an unspecified index. Your data will be downloaded and filtered on the client. Consider adding ".indexOn": "post/vote/moodTags/M1/key" at /Recommendations to your security rules for better performance.

但是，我在 firebase 站点的索引规则是:

"Recommendations":{
  ".indexOn": ["post/userFirebaseKey","post/user/firebaseKey","userFrom/firebaseKey","post/location/placeId","firebaseKey","placeId"],
  "post":{
    "vote":{
      "moodTags":{
        "$moodId":{
          ".indexOn": "key"
        }
      }
    }
  }
}

那么，当我使用子级别时，如何实际指定indexOn规则？

我的数据库:

+ Recommendations
  + idRec
    property1:''
    property2:''
    property3:''
    + post
      property21:''
      ...
      + vote
        + moodTags
          + M1
            key:'M1'
            name:''
            url:''
          + M2        
            ...

Answer 1

您似乎操作的级别太深了:毕竟您想要索引心情标签列表，而不是一个心情标签的内容。

这意味着您的规则必须看起来更像这样:

"Recommendations":{
   ".indexOn": ["post/userFirebaseKey","post/user/firebaseKey","userFrom/firebaseKey","post/location/placeId","firebaseKey","placeId"],
  "post":{
    "vote":{
      "moodTags":{
          ".indexOn": "key"
        }
      }
    }
  }
}

您可以在the official Google Firebase Docs中阅读这些索引规则。 ，也在 this helpful article on Medium并在 this Google Groups post where someone had a similar issue .