Firebase indexOn warning for dynamic values

Question

Here are my Firebase database structure and my query.

And my query on this structure is:

var messageRef = databaseRef.child(`/messagesThread/-KdzCvVW5icW7ZuSIAxV`);

messageRef.orderByChild(`/readBy/{userId}`).equalTo(false).on("child_added", (snapshots)=>{
  console.log("Unread messages = " + snapshots.numChildren());
});

But above query giving me warning as

FIREBASE WARNING: Using an unspecified index. Consider adding ".indexOn": "readBy/{userId}".

So how to add this indexOn with dynamic {userId}?

score 3 · Accepted Answer · answered Feb 28 '17 at 11:41

3

Since indexing on a wildcard is not great, you can modify the structure and then index:

---readBy-+
          |
           294jjfouurjkfJDGLS+
                             |
                            isRead: true

Now you can add to the security rules:

"readBy": {
  ".indexOn": "isRead"
}

answered Feb 28 '17 at 11:41

Idan

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1

Yup. Also see my answer here for a longer explanation: http://stackoverflow.com/questions/40656589/firebase-query-if-child-of-child-contains-a-value – Frank van Puffelen Feb 28 '17 at 15:08

Firebase indexOn warning for dynamic values

1 Answers1