Question

我正在研究这个4链式下拉选项，一切正常，这就是它的工作原理。

学期：你选择一个学期

主题：选择一个学期后，选择一个主题

部分：选择主题后，您可以选择哪个部分

教授：选择一个部分后，根据所选部分选择哪个教授。

问题在于，当涉及到教授时，它会从数据库中取代所有教授，而不是指派给该课程和部分的教授。例如，我这样做：

学期：2015年秋季

主题：csis 330

部分：1

教授：应该展示杰森，但它显示所有教授1号部分的教授（问题是它需要检查教授所选科目和所选科目的教授，不仅仅是因为它带来所有教授教授科目编号1）

我希望你明白了。

以下是我的代码：

func.php

<html>
<?php
//**************************************
//     Page load dropdown results     //
//**************************************
function getTierOne()
{
    $result = mysql_query("SELECT DISTINCT semester FROM three_drops") 
    or die(mysql_error());

      while($tier = mysql_fetch_array( $result )) 

        {
           echo '<option value="'.$tier['semester'].'">'.$tier['semester'].'</option>';
        }

}

//**************************************
//     First selection results     //
//**************************************
if($_GET['func'] == "drop_1" && isset($_GET['func'])) { 
   drop_1($_GET['drop_var']); 
}

function drop_1($drop_var)
{  
    include_once('db.php');
    $result = mysql_query("SELECT DISTINCT subject FROM three_drops WHERE semester='$drop_var'") 
    or die(mysql_error());
    ?>
        <br /><br />  <label for="subject" accesskey="s">Subject</label>&nbsp;&nbsp;&nbsp;&nbsp;
        <?php
    echo '<select name="drop_2" id="drop_2">
          <option value=" " disabled="disabled" selected="selected">Choose one</option>';

           while($drop_2 = mysql_fetch_array( $result )) 
            {
              echo '<option value="'.$drop_2['subject'].'">'.$drop_2['subject'].'</option>';
            }



    echo '</select>';
    echo "<script type=\"text/javascript\">
$('#wait_2').hide();
    $('#drop_2').change(function(){
      $('#wait_2').show();
      $('#result_2').hide();
      $.get(\"func.php\", {
        func: \"drop_2\",
        drop_var: $('#drop_2').val()
      }, function(response){
        $('#result_2').fadeOut();
        setTimeout(\"finishAjax_section('result_2', '\"+escape(response)+\"')\", 400);
      });
        return false;
    });
</script>";
}


//**************************************
//     Second selection results     //
//**************************************
if($_GET['func'] == "drop_2" && isset($_GET['func'])) { 
   drop_2($_GET['drop_var']); 
}

function drop_2($drop_var)
{  
    include_once('db.php');
    $result = mysql_query("SELECT DISTINCT section FROM three_drops WHERE subject='$drop_var'") 
    or die(mysql_error());
        ?>
        <br /><br />  <label for="section" accesskey="s">Section</label>&nbsp;&nbsp;&nbsp;&nbsp;
        <?php
    echo '<select name="drop_3" id="drop_3">
          <option value=" " disabled="disabled" selected="selected">Choose one</option>';

           while($drop_3 = mysql_fetch_array( $result )) 
            {
              echo '<option value="'.$drop_3['section'].'">'.$drop_3['section'].'</option>';
            }

                echo '</select>';
    echo "<script type=\"text/javascript\">
$('#wait_3').hide();
    $('#drop_3').change(function(){
      $('#wait_3').show();
      $('#result_3').hide();
      $.get(\"func.php\", {
        func: \"drop_3\",
        drop_var: $('#drop_3').val()
      }, function(response){
        $('#result_3').fadeOut();
        setTimeout(\"finishAjax_professor('result_3', '\"+escape(response)+\"')\", 400);
      });
        return false;
    });
</script>";
}


//**************************************
//     Third selection results     //
//**************************************
if($_GET['func'] == "drop_3" && isset($_GET['func'])) { 
   drop_3($_GET['drop_var']); 
}

function drop_3($drop_var)
{  
    include_once('db.php');
    $result = mysql_query("SELECT DISTINCT professor FROM three_drops WHERE section='$drop_var'") 
    or die(mysql_error());
        ?>
        <br /><br />  <label for="professor" accesskey="s">Professor</label>&nbsp;&nbsp;&nbsp;&nbsp;
        <?php
    echo '<select name="drop_4" id="drop_4">
          <option value=" " disabled="disabled" selected="selected">Choose one</option>';

           while($drop_4 = mysql_fetch_array( $result )) 
            {
              echo '<option value="'.$drop_4['professor'].'">'.$drop_4['professor'].'</option>';
            }

    echo '</select> ';
}
?>
</html>

的index.php

<?php 
  include('db.php');
  include('func.php');
  ?>
 <div>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
    $('#wait_1').hide();
    $('#drop_1').change(function(){
      $('#wait_1').show();
      $('#result_1').hide();
      $.get("func.php", {
        func: "drop_1",
        drop_var: $('#drop_1').val()
      }, function(response){
        $('#result_1').fadeOut();
        setTimeout("finishAjax('result_1', '"+escape(response)+"')", 400);
      });
        return false;
    });
});

function finishAjax(id, response) {
  $('#wait_1').hide();
  $('#'+id).html(unescape(response));
  $('#'+id).fadeIn();
}
function finishAjax_section(id, response) {
  $('#wait_2').hide();
  $('#'+id).html(unescape(response));
  $('#'+id).fadeIn();
}
function finishAjax_professor(id, response) {
  $('#wait_3').hide();
  $('#'+id).html(unescape(response));
  $('#'+id).fadeIn();
}
</script>
      <label for="semester" accesskey="s">Semester</label>&nbsp;
    <select name="drop_1" id="drop_1">

      <option value="" selected="selected" disabled="disabled">Select a Category</option>

      <?php getTierOne(); ?>

    </select> 

    <span id="wait_1" style="display: none;">
    <img alt="Please Wait" src="ajax-loader.gif"/>
    </span>
    <span id="result_1" style="display: none;"></span>
    <span id="wait_2" style="display: none;">
    <img alt="Please Wait" src="ajax-loader.gif"/>
    </span>
    <span id="result_2" style="display: none;"></span>
     <span id="wait_3" style="display: none;">
    <img alt="Please Wait" src="ajax-loader.gif"/>
    </span>
        <span id="result_3" style="display: none;"></span>

</div>

数据库是这样的：

semester  | subject  | section | professor 
Fall-2015 | ELEG-330 |    1    | Jason     
Fall-2015 | ELEG-330 |    2    | Michael
Fall-2015 | ELEG-210 |    1    | kyle

例如上面的例子，如果学期是2015年秋季，主题是eleg-330和第1部分，教授会显示jason和kyle都不正确。

提前致谢。

Answer 1

首先，您需要更改$.get()中的function drop_2($drop_var)，以便传递其他数据

function drop_2($drop_var)
{  
    include_once('db.php');
    ...[your other code]...

                echo '</select>';
    echo "<script type=\"text/javascript\">
$('#wait_3').hide();
    $('#drop_3').change(function(){
      $('#wait_3').show();
      $('#result_3').hide();
      $.get(\"func.php\", {
        func: \"drop_3\",
        drop_var1: $('#drop_1').val(), //semester
        drop_var2: $('#drop_2').val(), //subject
        drop_var3: $('#drop_3').val()  //section
      }, function(response){
        $('#result_3').fadeOut();
        setTimeout(\"finishAjax_professor('result_3', '\"+escape(response)+\"')\", 400);
      });
        return false;
    });
</script>";
}

然后在function drop_3()中，您需要添加其他参数

//**************************************
//     Third selection results     //
//**************************************
if($_GET['func'] == "drop_3" && isset($_GET['func'])) { 
   drop_3($_GET['drop_var1'],$_GET['drop_var2'],$_GET['drop_var3']); 
}

function drop_3($drop_var1,$drop_var2,$drop_var3)
{  
    include_once('db.php');
    $result = mysql_query("SELECT DISTINCT professor FROM three_drops WHERE  semester='$drop_var1' AND subject='$drop_var2' AND section='$drop_var3'") 
    or die(mysql_error());
        ?>
        ...[rest of your code]...
}

Answer 2

您没有在每个后续步骤中传递先前的信息。将主题传递给第三个函数，将其添加到get中，如下所示：

$('#drop_3').change(function(){
    $('#wait_3').show();
    $('#result_3').hide();
    $.get(\"func.php\", {
        func: \"drop_3\",
        drop_var: $('#drop_3').val(),
        prev_var: '".$drop_var."' // added $prev_var here
    }, function(response){
        $('#result_3').fadeOut();
        setTimeout(\"finishAjax_professor('result_3', '\"+escape(response)+\"')\", 400);
    });
    return false;
});

然后将其传递给第三个函数中的第二个参数，并在查询中使用它：

if($_GET['func'] == "drop_3" && isset($_GET['func'])) { 
   drop_3($_GET['drop_var'], $_GET['prev_var'); 
}
function drop_3($drop_var, $prev_var) // $prev_var here
{  
    include_once('db.php');
    $result = mysql_query("SELECT DISTINCT professor FROM three_drops WHERE section='$drop_var' AND subject='$prev_var'") // $prev_var here
    or die(mysql_error());

    //etc.
}

链式选择下拉小错误

2 个答案: