Firebase時間戳范圍內的嵌套查詢

Question

我在使用嵌套查詢時遇到問題：

firebase.database().ref().child('panels').child('qa')
      .orderByChild('completed')
      .startAt(firstDay.getTime()) // January 1st, 2016
      .endAt(lastDay.getTime()) // current date (aug, 25th 2016)
      .once('value', function(snapshot) {
        $log.log(snapshot.numChildren());
      });

返回0

如果我將完成放置在節點的第一級，那么它將起作用：

firebase.database().ref().child('panels')
      .orderByChild('completed')
      .startAt(firstDay.getTime()) // January 1st, 2016
      .endAt(lastDay.getTime()) // current date (aug, 25th 2016)
      .once('value', function(snapshot) {
        $log.log(snapshot.numChildren());
      });

返回10;

有什么想法為什么嵌套解決方案不起作用？

Answer 1

好的，問題是：

   firebase.database().ref().child('panels')
    .orderByChild('qa/completed')
    .startAt(firstDay.getTime()) // January 1st, 2016
    .endAt(lastDay.getTime()) // current date (aug, 25th 2016)
    .once('value', function(snapshot) {
      $log.log(snapshot.numChildren());
    });

您必須orderByChild嵌套數據