Question

我试图从数据库数据创建图表但是当我调用数据时它不会显示。我想问一下我的代码有什么问题吗？ sql语句是错误的，因为我已经尝试检查代码，看起来一切看起来都很棒。现在我有三个表，即评论，用户和upload_medicine。审查表是链接用户和upload_medicine主键，分别是user_id和medicine_id。在图表中，我打算从评论表中调用用户总数，并从upload_medicine调用疾病名称。

//connect to database
$db=mysqli_connect("localhost","root","","authen");

  $sql4="select * from review left join upload_medicine on review.medicineid=upload_medicine.medicine_id left join users on review.userid = users.user_id ";
$result4=mysqli_query($db,$sql4);

?>
<!DOCTYPE html>
<html>
<head>
  <title> TCHM </title>
  <link rel="stylesheet" type="text/css" href="style01.css"/>
     <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
    <script type="text/javascript">
      google.charts.load('current', {'packages':['corechart']});
      google.charts.setOnLoadCallback(drawChart);

      function drawChart() {

        var data = google.visualization.arrayToDataTable([
          ['Bil', 'Illness'],
          <?php
            while($row=mysqli_fetch_assoc(result4)){
                echo"['".$row['sum(userid)']."',".$row['illness_name']."],";
            }
            ?>
        ]);

        var options = {
          title: 'The total user faced the illness'
        };

        var chart = new google.visualization.PieChart(document.getElementById('piechart'));

        chart.draw(data, options);
      }

  </script>

PHP -Google图表无法从数据库中读取我的数据

0 个答案: