如何从firebase获取填充数据的表

Question

下面的代码使我能够使用JSON文件中的数据填充数据表。我现在正尝试从googles firebase数据库中的数据填充数据。在googles firebase数据库中推送新数据附带了push.key，因此，由于我缺乏使用firebase的经验，我很难在表格中填充数据。

结果应如下：

以下代码从firebase数据生成object.arrays。 1表示数据的第1列

var columns = [];
var data = [];
firebase.database().ref("DataSet2").once("value", function(snap){
    snap.forEach(snapshot => {
        Object.keys(snapshot.val()).map(k => {
              columns.push(Object.assign({}, {"data":k}))
              data.push(Object.assign({}, {k:snapshot.val()[k]}))
        })
    })
})
console.log(columns)
console.log(data)

我希望以下会填充表格，但它没有（没有任何反应。

任何想法如何实现这一目标？

$("#example").DataTable({
ajax: {
        url: 'test.json',    
        dataSrc: data 
      },
      "columns": columns
});

html：

    <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>MK</title>
    <!-- DATATABLES -->
    <link rel="stylesheet" type="text/css" href="https://www.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/1.10.16/css/dataTables.bootstrap.min.css">
    <!-- RESPONSIVENESS -->
    <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/responsive/2.2.1/css/responsive.dataTables.min.css">
    <!-- DATETIMEPICKER -->
    <link rel="stylesheet" type="text/css" href="https://rawgit.com/smalot/bootstrap-datetimepicker/master/css/bootstrap-datetimepicker.css">
    <!-- DATATABLES FREE EDITOR -->
    <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/buttons/1.5.1/css/buttons.dataTables.min.css">
    <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/select/1.2.4/css/select.dataTables.min.css">
    <!-- MYCSS -->
    <link rel="stylesheet" type="text/css" href="style.css">
</head>

<body>
    <input type='text' id="dateTime" class="dateTime" placeholder="Date Time" readonly>

    <div id='tableContainer'>

        <table id="example" class="table table-striped table-bordered" cellspacing="0" width="100%">
            <thead>
                <tr>
                    <th></th><!-- COLUMN FOR RESPONSIVENESS -->
                    <th>INBOUND</th>
                    <th>ORG</th>
                    <th>STA</th>
                    <th>ETA</th>
                    <th>OUTBOUND</th>
                    <th>DES</th>
                    <th>STD</th>
                    <th>ETD</th>
                    <th>REMARKS</th>
                    <th>GATE</th>
                    <th>WHS</th>
                    <th>TEST</th>
                    <th>ARR</th>
                </tr>
            </thead>
        </table>

    </div>

</body>
<!-- FIREBASE -->
<script src="https://www.gstatic.com/firebasejs/4.9.0/firebase.js"></script>
<!-- JQUERY -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<!-- DATATABLES -->
<script src="https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js"></script>
<script src="https://cdn.datatables.net/1.10.16/js/dataTables.bootstrap.min.js"></script>
<!-- RESPONSIVENESS -->
<script src="https://cdn.datatables.net/responsive/2.2.1/js/dataTables.responsive.min.js"></script>
<!-- DATETIMEPICKER -->
<script src="https://rawgit.com/smalot/bootstrap-datetimepicker/master/js/bootstrap-datetimepicker.min.js"></script>
<!-- DATATABLES FREE EDITOR -->
<script src="https://cdn.datatables.net/buttons/1.5.1/js/dataTables.buttons.min.js"></script>
<script src="https://cdn.datatables.net/select/1.2.4/js/dataTables.select.min.js"></script>
<script src="datatablesAltEditor.js"></script>
<!-- MYJS -->
<script src="libs.js"></script>

JS：

 $("#example").DataTable({
select: 'single',
responsive: true,
paging: true,
pageLength: 25,
order: [
    [3, 'asc']
],
ajax: {
    url: 'dbs.json',
    dataSrc: 'dataset1'
},
"columns": [{
        "data": null,
        defaultContent: '',
        className: 'control',
        orderable: false
    }, // RESPONSIVENESS
    {
        "data": "inbound"
    },
    {
        "data": "org"
    },
    {
        "data": "sta"
    },
    {
        "data": "eta"
    },
    {
        "data": "outbound"
    },
    {
        "data": "des"
    },
    {
        "data": "std"
    },
    {
        "data": "etd"
    },
    {
        "data": "remarks"
    },
    {
        "data": "gate"
    },
    {
        "data": "whs"
    },
    {
        "data": null,
        render: function(data, type, row) {
            return data.flight + ' ' + data.org;
        }
    },
    {
        data: "arr"
    }
]

});

JSON：

{
"dataset1": [{
    "inbound": "MK509",
    "org": "ICN",
    "sta": "12DEC17 16:45",
    "eta": "12DEC17 17:35",
    "outbound": "MK509",
    "des": "ARN",
    "std": "12DEC17 18:45",
    "etd": "12DEC17 19:35",
    "remarks": "DELAYED",
    "gate": "S96",
    "whs": "T11",
    "arr": "X"
}, {
    "inbound": "RT8101",
    "org": "DOH",
    "sta": "12DEC17 08:25",
    "eta": "12DEC17 08:25",
    "outbound": "RT8101",
    "des": "ORD",
    "std": "12DEC17 10:25",
    "etd": "12DEC17 10:25",
    "remarks": "COW CHARTER",
    "gate": "S94",
    "whs": "T9",
    "arr": "X"
}],
"dataset2": [{
    "flight": "KIKKER1",
    "org": "ICN",
    "sta": "12DEC17 16:45",
    "eta": "12DEC17 17:35",
    "flight": "KE509",
    "des": "ARN",
    "std": "12DEC17 18:45",
    "etd": "12DEC17 19:35",
    "remarks": "DELAYED",
    "gate": "S96",
    "whs": "T11",
    "ciss": "X",
    "arr": "X"
}, {
    "flight": "KIKKER2",
    "org": "DOH",
    "sta": "12DEC17 08:25",
    "eta": "12DEC17 08:25",
    "flight": "QR8101",
    "des": "ORD",
    "std": "12DEC17 10:25",
    "etd": "12DEC17 10:25",
    "remarks": "COW CHARTER",
    "gate": "S94",
    "whs": "T9",
    "ciss": "X",
    "arr": "X"
}]

firebase中的数据如下：

列和数据数组的结果如下：

COLUMNS

数据