Question

我试图通过使用谷歌图表以折线图的形式显示mysql数据。我认为问题是我试图格式化谷歌图表的数据时的部分。我的代码出了什么问题？

$sth = mysql_query("SELECT * FROM real_price");

$data = array (
    'cols' => array(  
        array('id' => 'period', 'label' => 'Period', 'type' => 'string'), 
        array('id' => 'demand', 'label' => 'Demand(MW)', 'type' => 'number')

    ),
    'rows' => array();
);

while ($res = mysql_fetch_assoc($sth)){
 $data['rows'][] = array('c' => array(
        array('v' => $res['Period']),
        array('v' => $res['Demand(MW)'])
    ));
}
$json = json_encode($data);
?>
<html>
  <head>
    <script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script type="text/javascript">
      google.load("visualization", "1", {packages:["corechart"]});
      google.setOnLoadCallback(drawChart);
      function drawChart() {
        var data = google.visualization.DataTable(<?php echo $json ?>);

        var options = {
          title: 'Price information'
        };

        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));

        chart.draw(data, options);
      }
    </script>
  </head>
  <body>
    <div id="chart_div" style="width: 900px; height: 500px;"></div>
  </body>
</html>

Answer 1

我认为json格式错误，应该是

     $sth = mysql_query("SELECT * FROM real_price");
     $data = array(array("Period", "Demand(MW)"));

     while ($res = mysql_fetch_assoc($sth)){
             $data[] = array($res['Period'], $res['Demand(MW)']);
     }

     $json = json_encode($data);

MYSQL到谷歌图表（折线图）

1 个答案: