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javascript - 来自 mysql、php/JQuery 的 Google 折线图

转载 作者：行者123 更新时间：2023-11-29 21:47:10 26 4
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我已经研究了一些程序，现在我需要从 MySQL 获取数据并用 HTML/PHP 显示它。我使用这个 mysql.php 文件从 MySQL 获取数据:

<?php
    $hostname = "localhost";
    $database = "database";
    $username = "username";
    $password = "password";
    $connect = mysql_connect($hostname, $username, $password)

    or die('Could not connect: ' . mysql_error());
    $bool = mysql_select_db($database, $connect);
    if ($bool === False){
       print "can't find $database";
    }

    $query = "SELECT * FROM  `table` ORDER BY timestamp LIMIT 0 , 100";
    $result = mysql_query($query) or die("SQL Error 1: " . mysql_error());
    // get data and store in a json array
    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
        $values[] = array(
            'timestamp' => $row['timestamp'],
            'temperature' => $row['temperature'],
          );
    }

    echo json_encode($values);
?>

然后我尝试将其显示到谷歌图表:

<html>
<body>
<script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script type="text/javascript">

    // Load the Visualization API and the piechart package.
    google.load('visualization', '1', {'packages':['corechart']});

    // Set a callback to run when the Google Visualization API is loaded.
    google.setOnLoadCallback(drawChart);

    function drawChart() {
      var jsonData = $.ajax({
          url: "http://localhost:8081/xampp/testi/mysql.php",
          dataType:"json",
          async: false
          }).responseText;

      // Create our data table out of JSON data loaded from server.
      var data = new google.visualization.DataTable(jsonData);

      // Instantiate and draw our chart, passing in some options.
      var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
      chart.draw(data, {width: 400, height: 240});
    }

    </script>
    <div id="chart_div"></div>
</body>
</html>

但它只是给出错误:

Open photo

JSON 格式有点不对劲，但是怎么回事呢？

最佳答案

您的 JSON 格式应如下所示

{
"cols": [
    {"id":"","label":"Topping","pattern":"","type":"string"},
    {"id":"","label":"Slices","pattern":"","type":"number"}
  ],
"rows": [
    {"c":[{"v":"Mushrooms","f":null},{"v":3,"f":null}]},
    {"c":[{"v":"Onions","f":null},{"v":1,"f":null}]},
    {"c":[{"v":"Olives","f":null},{"v":1,"f":null}]},
    {"c":[{"v":"Zucchini","f":null},{"v":1,"f":null}]},
    {"c":[{"v":"Pepperoni","f":null},{"v":2,"f":null}]}
  ]
}

因此，当您尝试将 JSON 转换为 DataTable 时，您不会得到任何返回，因为它的格式不正确。更多内容请阅读此处。

尝试格式化您的 JSON，例如

var jsonData = {}
jsonData.cols = [
      {"label":"Date w/ time", "type":"date"},
      {"label":"Temp", "type":"number"}
  ]
jsonData.rows = [
     {"c":[{"v":new Date(2015, 11, 1, 12, 23)}, {"v":50}]},
     {"c":[{"v":new Date(2015, 11, 1, 12, 24)}, {"v":75}]}
]

关于javascript - 来自 mysql、php/JQuery 的 Google 折线图，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34019009/

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