swift - FIRDatabaseReference messagesQuery.queryEqualToValue 什么都不返回

Question

我正在使用 JSQMessagesViewController 聊天<​​/p>

以下在快照中返回null

private func observeMessages() {

    let messagesQuery = messageRef.queryLimitedToLast(50)

    let query = messagesQuery.queryEqualToValue("100", childKey: "recipient")

    query.observeEventType(.ChildAdded, withBlock: { snapshot in

        let id = snapshot.value!["sender"] as! String
        let text = snapshot.value!["text"] as! String
        let recipient = snapshot.value!["recipient"] as! String
        self.addMessage(id, text: text, recipient:recipient)
        self.finishReceivingMessage()
    })
}

返回数据如下

private func observeMessages() {

    let messagesQuery = messageRef.queryLimitedToLast(50)

    messagesQuery.observeEventType(.ChildAdded, withBlock: { snapshot in

        let id = snapshot.value!["sender"] as! String
        let text = snapshot.value!["text"] as! String
        let recipient = snapshot.value!["recipient"] as! String
        self.addMessage(id, text: text, recipient:recipient)
        self.finishReceivingMessage()
    })
}

我需要按收件人过滤，我的 firebase 数据库树如下所示

我一直在谷歌和 SO 这里搜索，但找不到任何解决方案

Answer 1

您正在使用 queryEqualToValue 的变体，它无法满足您的要求。

改用这个:

let query = messagesQuery. queryOrderedByChild("recipient").queryEqualToValue("100")