使用带有PHP数据的Google图表

我正在尝试使用Google图表生成一个饼图，我想使用的数据在MySQL数据库中，因此我创建了一个脚本来获取数据并将其解析为JSON，理想情况下，JSON将填充该图

我已经创建了这个脚本，并检查它是否接收到数据，它是否是JSON格式的，但我得到的只是“Table has no columns”，有人知道我哪里出错了吗

显示图形的页面

      <!--Load the AJAX API-->
      <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
      <script type="text/javascript">

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

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

        // Callback that creates and populates a data table,
        // instantiates the pie chart, passes in the data and
        // draws it.
        function drawChart() {
          var jsonData = $.ajax({
              url: "scripts/charts/popularColours.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>

您可以看到，这是返回的数据

[{"veh_colour":null,"col":206},{"veh_colour":"Black Pearl","col":9},{"veh_colour":"dynamic red","col":8},{"veh_colour":"Battersea Blue","col":6},{"veh_colour":"Arctic White","col":6},{"veh_colour":"Laser Blue","col":5}]

---

您是否尝试对响应进行正确编码？现在，响应作为默认文本响应发送，但您可以让PHP告诉您的浏览器/客户端响应实际上是JSON：

在echo之前添加此项应做到：

标题（“内容类型：application/json”）；

然而，jQuery可能已经猜到了这一点。也许问题出在JS方面。您是否尝试过这样的方式，而不是直接呼叫.responseText

$.ajax({
//你的参数
})
.完成（功能（数据）{
//数据应该是JSON响应
});

为了从json创建google数据表，它必须采用特定的格式。否则，您可以提供一个简单的数组并使用它来创建数据表。注意：

$上的
async:false
。ajax

已被弃用，请改用

done

回调。检查。。。

$dsn = "";
$options = [
  PDO::ATTR_EMULATE_PREPARES   => false, // turn off emulation mode for "real" prepared statements
  PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION, //turn on errors in the form of exceptions
  PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC, //make the default fetch be an associative array
];
try {
  $pdo = new PDO($dsn, "dbu300121", "3DD63tJXYpP%", $options);
} catch (Exception $e) {
  error_log($e->getMessage());
  exit('There has been an unexpected error, please try again last if the issue continues then contact your IT Support team.'); //something a user can understand
}

$statement = $pdo->prepare("SELECT veh_colour, COUNT(*) as col FROM cst_vehicle GROUP BY veh_colour ORDER BY 2 DESC LIMIT 6");
$statement->execute();
$results = $statement->fetchAll(PDO::FETCH_ASSOC);
$json = json_encode($results);
echo $json;

[{"veh_colour":null,"col":206},{"veh_colour":"Black Pearl","col":9},{"veh_colour":"dynamic red","col":8},{"veh_colour":"Battersea Blue","col":6},{"veh_colour":"Arctic White","col":6},{"veh_colour":"Laser Blue","col":5}]