折线图如果全部为Null则隐藏列

我正在从表中获取数据并创建图表。但是，如果列的所有值都为空/null，则会给我一个轴#0的数据列的类型不能为字符串如果一列的所有值都为null，是否有方法可以忽略/隐藏该列来创建图表？

google.charts.load('current', {
  callback: function () {
    var data = google.visualization.arrayToDataTable([
      ['vdate', 'THS', 'FT3', 'FT4'],
      [new Date('08/01/2016'), 10, null, 30],
      [new Date('08/02/2016'), 40, null, 60],
      [new Date('08/03/2016'), 70, null, 90]
    ]);
    var chartColors = ['#000000', '#D20000', '#5CB85C'];
    var options = {
      legendTextStyle: {color: '#757575'},
      fontName: 'Didact Gothic',
      curveType: 'function',
      height: 300,
      pointSize: 5,
      interpolateNulls: true,
      colors: chartColors,
      hAxis: {title: 'Visit', titleTextStyle: {fontName: 'Didact Gothic', color: '#757575'}, textStyle:{color: '#757575'}},
      vAxis: {title: 'Prices', titleTextStyle: {fontName: 'Didact Gothic', color: '#757575'}, textStyle:{color: '#757575'}, viewWindow: {min:0}}
    };
    var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));
    data.addColumn({type: 'string', role: 'annotation'});
    var view = new google.visualization.DataView(data);
    var initialchart =[0];
    var selectedColors = [];
    if($("#kolom1").is(':checked')) {
    	initialchart.push(1,{ calc: "stringify", sourceColumn: 1, type: "string", role: "annotation"});
    	selectedColors.push(chartColors[0]);
    }
	if ($("#kolom2").is(':checked')) {
    	initialchart.push(2,{ calc: "stringify", sourceColumn: 2, type: "string", role: "annotation"});
      selectedColors.push(chartColors[1]);
    }
	if ($("#kolom3").is(':checked')) {
    	initialchart.push(3,{ calc: "stringify", sourceColumn: 3, type: "string", role: "annotation"});
      selectedColors.push(chartColors[2]);
    }
    view.setColumns(initialchart);
    options.colors = selectedColors;
    var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));
    chart.draw(view, options);
    $(".checkbox").change(function() {
      view = new google.visualization.DataView(data);
      var checkchart =[0];
      var selectedColors = [];
      if($("#kolom1").is(':checked')) {
        checkchart.push(1,{calc: "stringify", sourceColumn: 1, type: "string", role: "annotation"});
        selectedColors.push(chartColors[0]);
      }
      if($("#kolom2").is(':checked')) {
        checkchart.push(2,{calc: "stringify", sourceColumn: 2, type: "string", role: "annotation"});
        selectedColors.push(chartColors[1]);
      }
      if($("#kolom3").is(':checked')) {
        checkchart.push(3,{calc: "stringify", sourceColumn: 3, type: "string", role: "annotation"});
        selectedColors.push(chartColors[2]);
      }
      view.setColumns(checkchart);
      options.colors = selectedColors;
      chart.draw(view, options);
    });
  },
  packages: ['corechart']
});

.exams {
  padding: 5px;
  background: #a2a2a2;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="checkboxes" style="min-height: 100px;">
  <input type="checkbox" class="checkbox" style="display: none;" id="kolom1" checked="checked" /><label class="exams" for="kolom1"><span class="check_icon"></span>TSH</label>
  <input type="checkbox" class="checkbox" style="display: none;" id="kolom2" checked="checked" /><label class="exams" for="kolom2"><span class="check_icon"></span>FT3</label>
  <input type="checkbox" class="checkbox" style="display: none;" id="kolom3" checked="checked" /><label class="exams" for="kolom3"><span class="check_icon"></span> FT4</label>
</div>
<div name="curve_chart" id="curve_chart"></div>

回答后更新：

我确实尝试过这个答案，如果其中一列为空，它将显示一个空图表正如我所说，我从一个表中获取数据并创建图表。我的data.addRows正确吗？

修复null：

我发现问题出在哪里，php变量为null传递空格，所以每行的最后一个值都是错误的，*here]我用php if is_null修复了它，并更新了下面的代码。

while($row = mysqli_fetch_array($results)){
if (is_null($row['check_tsh']) {$check_tsh = "null";}
if (is_null($row['check_ft3']) {$check_ft3 = "null";}
if (is_null($row['check_ft4']) {$check_ft4 = "null";}
$chartentry .= "['".date("d/m/Y", strtotime($row['vdate']))."', ".$check_tsh.", ".$check_ft3.", ".$check_ft4."],";
}
//chartentry Array: ['02/08/2016', 100,, 300],['03/08/2016', , , ],['04/08/2016', , , ],['05/08/2016', , , ]
var data = new google.visualization.DataTable();
data.addColumn('string', 'vdate');
    data.addColumn('number', 'THS');
    data.addColumn('number', 'FT3');
    data.addColumn('number', 'FT4');
data.addRows([<?php echo $chartentry ?>]);