Question

我有一个从数据库填充的select元素，当我选择一个元素时，我想向我展示与该行相关的另一列的其他数据。

例如：在下拉列表中我有：苹果，香蕉，梨

当我选择苹果时，我想从数据库中选择列＆＃39;总计＆＃39;这告诉我我剩下多少苹果。

我想，我应该使用Javascript-Ajax？或者是用PHP做另外一种方式。

提前致谢！

<?php include("db.php"); ?>
<!DOCTYPE html>
<html>
<head>
    <script type="text/javascript">
    $(document).ready(function() {
        $('select').material_select();
    }); 

    function myFunction() {
        if (document.getElementById('selectid').value == "other") {
            var x = document.createElement("INPUT");
            x.setAttribute("type", "text");
            x.setAttribute("value", "");
            x.setAttribute("placeholder", "Write another");
            x.setAttribute("class", "input-field col s12");
            document.getElementById("myDIV").appendChild(x);
        }
    } 
    </script>
</head>

<body>
    <div id="myDIV" class="input-field col s4">
    <?php
    $sql12 = "select * from fruitswhere total>0 && spent=1";
    $res1 = mysqli_query($conn, $sql12) or die("Error");
    $select = '<select id="selectid" name="name" onchange="myFunction()"><option value = "" disabled selected> Choose </option>';
    while($row1 = mysqli_fetch_assoc($res1)) {
        $emri = $row1['name'];
    // $select.='<option value = "'.$row1['name'].'">'.$row1['name '].'</option>';
        $select .= '<option id="my_option" value="'.$name.'">'.$name.'</option>';
    }
    $select .= '<option value="other">other</option>';
    $select .= '</select>';
    echo $select;
    ?>
    </div>

    <div class="input-field col s4">
    <?php
    $query2 = "SELECT total FROM fruits WHERE name='$name'";
    $res2 = mysqli_query($conn, $query2);
    while($row2=mysqli_fetch_assoc($res2)){
        $all = $row2['total'];
    }
    ?>
    <input name="total" type="number" min="1">
    </div>
</body>
</html>

Answer 1

您可以设置一个简单的脚本来响应请求。例如，您可以创建fruitCount.php：

<?php
include('db.php');

$sql = 'SELECT total '.
       'FROM fruits '.
       'WHERE name="'.mysqli_real_escape_string($_POST['name']).'"';
$result = mysqli_query($conn, $sql);
if ($result != NULL) {
    $row = mysqli_fetch_assoc($result);
    print($row['total']);
} else {
    print(0);
}
die();

然后在页面上，您可以使用jQuery设置请求来自此资源的数据的click事件：

$('#selectid').change(function(){
        $.post('fruitCount.php',           // Server target for request
               { name: $(this).val() },    // POST payload
               function(resp){             // Handle response from server
                   $('#myDiv').html(resp); // Populate value to page
               });
    });

这是一种允许在服务器端正在发生变化的环境中使用最新值的实现。如果您只需要加载时的值，可以在OPTION元素上设置data-count属性并从中更新#myDiv：

$('#selectid').change(function(){
        $('#myDiv').html($(this).data('count'));
    });

如何实施它取决于您希望数据的实时性。

Answer 2

您好我找到了一个使用AJAX的解决方案，在这里，它完美无缺！

         <script language = "javascript" type = "text/javascript">
                  <!--
                     //Browser Support Code
                     function ajaxFunction(){
                        var ajaxRequest;  // The variable that makes Ajax possible!

                        try {
                           // Opera 8.0+, Firefox, Safari
                           ajaxRequest = new XMLHttpRequest();
                        }catch (e) {
                           // Internet Explorer Browsers
                           try {
                              ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
                           }catch (e) {
                              try{
                                 ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
                              }catch (e){
                                 // Something went wrong
                                 alert("Your browser broke!");
                                 return false;
                              }
                           }
                        }

                        // Create a function that will receive data
                        // sent from the server and will update
                        // div section in the same page.

                        ajaxRequest.onreadystatechange = function(){
                           if(ajaxRequest.readyState == 4){
                              var ajaxDisplay = document.getElementById('result');
                              ajaxDisplay.innerHTML = ajaxRequest.responseText;
                           }
                        }

                        var fruitName= document.getElementById('selectid').value;
                        var queryString = "?name=" + fruitName;

                        ajaxRequest.open("GET", "ajax_totali.php" + queryString, 
                        true);
                        ajaxRequest.send(null);

                      }
                     }
               </script>
    <body>
      <div id="myDIV" class="input-field col s4">

       <?php $sql12="select * from fruits";
     $res1=mysqli_query($conn,$sql12) or die( "Error");
    $select= '<select id="selectid" name="name onchange="ajaxFunction()"><option value="" disabled selected>Choose one fruit</option>';
    while ($row1=mysqli_fetch_assoc($res1)){
          $select.='<option value="'.$row1['name'].'">'.$row1['name'].'</option>';
      }
    $select.='</select>';
    echo $select; ?>
      </div>
      <div class="input-field col s4">
                <div id='result'></div>
              </div>

        </body>
      </html>

ajax_total.php

     <?php
      include('db.php');
      $sql = 'SELECT total '.
      'FROM fruits'.
      'WHERE name="'.$_GET['name'].'"';
      $result = mysqli_query($conn, $sql);
      if ($result != NULL) {
        $row = mysqli_fetch_assoc($result);
        // print($row['total']);
        $result=$row['total'];
        echo "<div style='color:red'>.$result.</div>";
      } else {
        print(0);
      }
      die();

     ?>

根据从下拉列表中选择的数据从数据库中选择数据

2 个答案: