Question

我的代码正常工作并显示数据。但是，当我添加谷歌图表时，它不会显示任何数据，也不会出现错误。我需要修改什么吗？它显示为空白页面。但是当我运行没有谷歌柱形图的代码时，它显示数据。

这里是我的密码

<?php
     include 'login_success.php';
     $user='root';
     $pass='';
     $db='mypro_bms';
     $conn = mysqli_connect('localhost',$user,$pass,$db);
     $count=0;

     if(isset($_POST['search'])){
     $txtStartDate=$_POST["txtStartDate"];

     $txtEndDate=$_POST["txtEndDate"];




     $q=mysqli_query($conn,"SELECT blood_group, SUM(blood_bag) as sum FROM donate where donation_date BETWEEN '$txtStartDate' and '$txtEndDate' group by blood_group");

      $count=mysqli_num_rows($q);



    }
      ?>
      <html>
      <head>
        <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([
              ['sum','blood_group'],
              <?php
              if ($count=="0") 
              {
                echo "No data";          }
                else
                {
                  while ($row=mysqli_fetch_array($q)) {
                   echo"['".$row['blood_group']."',".$row['sum']."],";
                  }
                }

          ?>
            ]);

如何从数据库检索数据以显示在Google柱形图中

0 个答案: