Question

我尝试使用Google Chart API使用数据库中的数据创建饼图。我的数据库有两列，一个是ID，一个是主要的。对于行，我有相应的ID和一些专业。我使用PHP来累计每个专业，然后将其转换为JSON。我的数据在JSON中看起来格式正确，但由于某种原因，饼图只显示MAJOR并且数字为2（100％）。它似乎没有正确阅读大公司的总数，我不明白为什么。我已经做了一些搜索，但找不到有类似问题的人。

这是输出的JSON

    {"cols":[{"label":"Major","type":"string"},{"label":"CS","type":"number"},{"label":"CIS","type":"number"},{"label":"Other","type":"number"}],"rows":[{"c":[{"v":"MAJOR"},{"v":2},{"v":1},{"v":2}]}]}

这是我的PHP

    $db = new PDO("mysql:host=".$servername.";dbname=".$dbname.";", $username, $password);

    $query = $db->query("SELECT 'MAJOR' as 'Major', SUM(IF(MAJOR = 'Computer Science',1,0)) as CS, SUM(IF(MAJOR = 'Computer Information Systems',1,0)) as CIS, SUM(IF(MAJOR = 'Other',1,0)) as Other FROM ages");


    $rows = array();
    $table = array();

    $table['cols'] = array(
        array('label' => 'Major', 'type' => 'string'),
        array('label' => 'CS', 'type' => 'number'),
        array('label' => 'CIS', 'type' => 'number'),
        array('label' => 'Other', 'type' => 'number')
    );


    while($r = $query->fetch()){
        $temp = array();
        $temp[] = array('v' => $r['Major']);
        $temp[] = array('v' => (int) $r['CS']);
        $temp[] = array('v' => (int) $r['CIS']);
        $temp[] = array('v' => (int) $r['Other']);

        $rows[] = array('c' => $temp);
    }

    $table['rows'] = $rows;

    $jsonTable = json_encode($table);

    echo $jsonTable;

这里是加载图表并使用JSON数据的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: "getData.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});
    }

使用Google Chart API从MySQL数据库创建饼图

0 个答案: