Question

我在beaglebone上使用mySQL来存储数据的项目温度。我能够使用php显示谷歌图表形式mysql但我无法实时更新它，任何人都可以帮助我，非常感谢。

<html>
<head>
    <title>BeagleBone Temperature</title>
    <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.arrayToDataTable([
            ['Time', 'Temperature'],
            <?php
                $con = mysqli_connect("localhost", "hoangviet", "hoangviet", "test");

                $query = "SELECT * FROM TempMeas"; // form table
                $result = mysqli_query($con, $query);

                mysqli_close($con);

                while ($row = mysqli_fetch_array($result))
                {
                    $time = $row['MeasTime'];
                    $temp = $row['Temp'];
                    echo "['$time', $temp],";
                }
            ?>
        ]);

        var options = {
          title: 'BeagleBone Measured Temperature',
          vAxis: { title: "Degrees Celsius" }
        };

        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

嗯。我想反向ajax会满足你的需要。其中一种类型是轮询，其中你不需要每隔30秒就通过ajax调用一个函数。它会在事件或触发功能的事物之后立即更新。现在有很多选项在做实时应用程序，一个是node.js也是角度js，如果你想实现实时web应用程序，你也可以读取套接字编程。希望有所帮助。

实时更新Google Chart，php，mySQL

1 个答案: