eg1.html

Question

我的HTML页面上有2个下拉列表：第一个下拉列表包含数据库列名称，第二个下拉列表将根据该名称填充即

我有一个包含字段的表：<Student Name, Degree, City>，以下是条目;

1. "A", "BS", "New York"
2. "B", "BS", "Chicago"
3. "C", "MS", "Boston"
4. "D", "MS", "New York"

所以我的第一个下拉列表将包含列名称，即“Degree”和“City”。

如果我选择“Degree”，第二个下拉列表应填充“BS”和“MS”，如果我选择“City”，第二个下拉列表应选择“New York”，“Boston”和“Chicago”。

我如何进行实施？

[添加我的代码]：

changeSecond(first)方法与您建议的方法完全相同

<body>
   <form method="POST" action="" name="mainForm">
      <table>
         <tr>
            <td> Filter by: </td>
            <td>
            <div id="first">
               <select onChange="changeSecond(this.value)">
                  <option value="1">All</option>
                  <option value="2">Degree</option>
                  <option value="3">City</option>
               </select>
            </td>
         </tr>
         <tr>
            <td>&nbsp</td>
            <td>
               <div id="second">
                  <select name="val">
                     <option value=""></option>
                  </select>
               </div>
            </td>
         </tr>
      </table>
   </form>
</body>

这是你建议的second_script.php：

<?
   $link = mysql_connect("localhost", "root", "");

   if (!$link)
   {
      die('Could not connect: ' . mysql_error());
   }
   if (mysql_select_db("myDatabase", $link))
   {
      $first=mysql_real_escape_string($_REQUEST["first"]);
      $query="SELECT ".$first." FROM myTable GROUP BY ".$first;
      $data=mysql_query($query);

      echo "<select id=\"second\">";
      while($row=mysql_fetch_row($data))
      {
         echo "<option value=\"".$row[0]."\">".$row[0]."</option>";
      }
      echo "</select>";
   }
   echo mysql_error();
?>

Answer 1

要根据其他内容填充的主文件的代码在下面的示例中，我显示了在父下拉列表中选择的该城市的子下拉列表中的地点

    <script type="text/javascript">
    function city_locality(val)
    {
    // alert (val);
    url="<?php echo $this->baseurl ?>/components/com_ezportal/includes/query.php";
    data="stid="+val;
$.post(url,data,function(data){
$("#locid").html(data);
});     
    }
    </script>
    <select name="filter_1state" id="filter_1state" onChange="city_locality(this.value)">
      <option value="0">-- Select City --</option>
      <option value="1">Lahore</option>
      <option value="2">Karachi</option>
      <option value="3">Islamabad</option>
      <option value="4">Quetta</option>
      <option value="5">Multan</option>
    </select>

文件query.php的代码

    <?php 
    $link = mysql_connect('localhost', 'root', '');
    mysql_select_db('mydatabase');
    if (isset($_POST['stid']))
    {
        $stid = $_POST['stid'];
        $query= mysql_query("SELECT id,ezcity FROM tbl_locality WHERE stateid = '".$stid."' GROUP BY ezcity"); 
    ?>
        <option value="0">-- Select Locality --</option>
    <?php
        while($row = mysql_fetch_array($query))
        {
    ?>
        <option value="<?php echo $row['id']?>"><?php echo $row['ezcity']?>        </option> 
        <?php
        }
    }
    ?>

Answer 2

您可以预先加载和隐藏所有下拉列表，并在第一个下拉列表中触发“更改”事件时显示它们，或者在同一个“更改”事件中有两个下拉列表并清空它。

如果您选择第二种方法，则应缓冲要在下拉列表中部分或全部插入的数据

Answer 3

如果您想要一个更加动态的解决方案（可以适应后台数据库的更改），您可以在页面上执行以下操作：

<script>
        function changeSecond(first){
        var xmlhttp;
        if (window.XMLHttpRequest)
          {// code for IE7+, Firefox, Chrome, Opera, Safari
          xmlhttp=new XMLHttpRequest();
          }
        else
          {// code for IE6, IE5
          xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
          }
        xmlhttp.onreadystatechange=function()
        {
          if (xmlhttp.readyState==4 && xmlhttp.status==200)
            {
            var res=xmlhttp.responseText;
            document.getElementById("second").innerHTML=res;
            }
          }
        xmlhttp.open("GET","second_script.php?first="+first,true);
        xmlhttp.send();
        }
        </script>
...
<select onChange="changeSecond(this.value)">
<option value="Degree">Degree</option>
<option value="City">City</option>
</select>
<div id="second"><select><option value=""></option></select></div>

然后是一个类似于：

的脚本

<?php
//database connection
$first=mysql_real_escape_string($_REQUEST["first"]);
$query="SELECT ".$first." FROM tablename GROUP BY ".$first;
$data=mysql_query($query);
echo "<select>";
while($row=mysql_fetch_row($data)){
echo "<option value=\"".$row[0]."\">".$row[0]."</option>";
}
echo "</select>";
?>

我想真正的灵活性你也想在另一个类似于上面的脚本中使用mysql_field_name动态填充第一个

Answer 4

您可以将ajax用于此目的

eg1.html

    <html>
    <head><title></title>
    </head>
    <body>
    <form method="POST" action="" name="mainForm">
    <table>
        <tr>
            <td> Filter by: </td>
            <td>
                <div id="first">
                   <select id="first_dropdown">
                      <option value="All">All</option>
                      <option value="Degree">Degree</option>
                      <option value="City">City</option>
                   </select>
            </td>
         </tr>
         <tr>
            <td>&nbsp</td>
            <td>
               <div id="second">
                  <select id="second_dropdown">

                  </select>
               </div>
            </td>
         </tr>
      </table>
   </form>
</body>
</html>

    <script src = "https://code.jquery.com/jquery-3.1.0.min.js"></script>
    <script type="text/javascript">
    $(document).ready(function(){
        $('#first_dropdown').change(function(){
            $.ajax({
                'type' : 'post',
                'url' : 'getDropdownOptions.php',
                'data': 'first=' + $(this).val(),
                'success' : function(data) {
                    $('#second_dropdown').html(data);
                }
             });
          });
        });
    </script>

getDropdownOptions.php

    <?php

    $link = mysql_connect("localhost", "root", "");

    if (!$link) {
        die('Could not connect: ' . mysql_error());
    }
    if (mysql_select_db("myDatabase", $link)) {
        $first = mysql_real_escape_string($_REQUEST["first"]);
        $query = "SELECT " . $first . " FROM myTable GROUP BY " . $first;
        $data  = mysql_query($query);

        $rtn_data = '';
        while ($row = mysql_fetch_row($data)) {
            $rtn_data .= "<option value=\"" . $row[0] . "\">" . $row[0] . "        </option>";
        }
        echo $rtn_data;
        exit;
    }
    echo mysql_error();

    ?>

Answer 5

Divyesh here, your answer is
==============================
edit.php
==============================
<!-- edit.php -->
<?php
include("config.php");
$id=$_REQUEST['id'];
echo $id;
$query=mysqli_query($con,"SELECT * FROM register r
INNER JOIN country c ON r.cuid = c.cuid
INNER JOIN state s ON r.sid = s.sid
INNER JOIN city ct ON r.cid = ct.cid where id='$id'");

while($r=mysqli_fetch_array($query))
{

     $fn=$r['firstname'];
     $add=$r['address'];
     $gn=$r['gender'];
     $hobby=$r['hobby'];
     $h=explode(',',$hobby);
     $q=array('reading','traveling','cricket','drawing');
     $country=$r['cuid'];
     $state=$r['sid'];
     $city=$r['cid'];
     echo $gn;
     $edu= $r['education'];
     $email=$r['email'];
     $pass=$r['password'];
     $conpass=$r['conpassword'];
     $phno=$r['phoneno'];
}

?>
<html>
<head>
    <script src="jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){

    $('#country').on('change',function(){
        var countryID = $(this).val();
        if(countryID){
            $.ajax({
                type:'POST',
                url:'ajaxData.php',
                data:'cuid='+countryID,
                success:function(html){
                    $('#state').html(html);
                    $('#city').html(html); 
                }
            }); 
        }else{
            $('#state').html(html);
            $('#city').html(html); 
        }
    });

    $('#state').on('change',function(){
        var stateID = $(this).val();
        if(stateID){
            $.ajax({
                type:'POST',
                url:'ajaxData.php',
                data:'sid='+stateID,
                success:function(html){
                    $('#city').html(html);
                }
            }); 
        }else{
            $('#city').html(html); 
        }
    });
});
</script>
</head>
    <body>
        <form method="post" action="update.php">
            <table border="1" align="center">
            <caption>Edit user data</caption>
            <tr>
                <td>First name</td>
                <td><input type="text" name="fn" value="<?php echo $fn;?>"></td>
            </tr>
            <tr>
                <td>Address</td>
                <td><input type="text" name="add" value="<?php echo $add;?>"></td>
            </tr>
            <tr>
                <td>Gender</td>
                <td><input type="radio" name="gn" value="male" <?php echo ($gn=='male')?'checked':'' ; ?> size="17">Male
                <input type="radio" name="gn" value="female" <?php echo ($gn=='female')?'checked':'' ; ?> size="17">Female
                </td>
            </tr>
            <tr>
                <td>Hobby</td>
                <td><input type="checkbox" name="hobby[]" value="reading" <?php if(in_array('reading',$h)){echo ("checked:'checked'");}?> >reading
                <input type="checkbox" name="hobby[]" value="traveling" <?php if(in_array('traveling',$h)){echo ("checked:'checked'");}?> >traveling
                <input type="checkbox" name="hobby[]" value="cricket" <?php if(in_array('cricket',$h)){echo ("checked:'checked'");}?> >cricket
                <input type="checkbox" name="hobby[]" value="drawing" <?php if(in_array('drawing',$h)){echo ("checked:'checked'");}?> >drawing</td>
            </tr>
            <?php
            $query = mysqli_query($con,"SELECT * FROM country");

            //Count total number of rows
            $rowCount = mysqli_num_rows($query);
            ?>
            <td>Country</td>
            <td><select name="country" id="country">
                <option value="<?php echo $country;?>"><?php echo $country;?></option>
                <?php
                if($rowCount > 0)
                {
                    while($row = mysqli_fetch_array($query))
                    { 
                        echo '<option value="'.$row['cuid'].'">'.$row['country'].'</option>';
                    }
                }
                else
                {
                    echo '<option value="">Country not available</option>';
                }
                ?>
            </select>
            </td></tr>
            <tr>
            <td>State</td>
            <td>
            <select name="state" id="state">
                <option value="<?php echo $state;?>"><?php echo $state;?></option>

            </select>
            </td></tr>
            <tr>
            <td>City</td>
            <td>
            <select name="city" id="city">
                <option value="<?php echo $city;?>"><?php echo $city;?></option>

            </select>
            </td>
            </tr>
            <tr>
                <td>Education</td>
                <td><input type="text" name="edu" value="<?php echo $edu;?>"></td>
            </tr>
                <td>Email</td>
                <td><input type="text" name="email" value="<?php echo $email;?>"></td>
            </tr>
            <tr>
                <td>Password</td>
                <td><input type="text" name="pass" value="<?php echo $pass;?>"></td>
            </tr>
            <tr>
                <td>Confirm password</td>
                <td><input type="text" name="conpass" value="<?php echo $conpass;?>"></td>
            </tr>
            <tr>
                <td>Phone no</td>
                <td><input type="text" name="phno" value="<?php echo $phno;?>"></td>
            </tr>
            <tr>
                <td><input type="hidden" name="id" value="<?php echo $id;?>">
                <input type="submit" name="update" value="update"></td>
            </tr>
            </table>
        </form>
    </body>
</html>

================
<h3>ajaxData.php</h3>
================
<!--ajaxData.php-->
<?php
//Include database configuration file
include("config.php");

if(isset($_POST["cuid"]) && !empty($_POST["cuid"]))
{
    //Get all state data
    $query = mysqli_query($con,"SELECT * FROM state WHERE cuid = ".$_POST['cuid']."");

    //Count total number of rows
    $rowCount = mysqli_num_rows($query);

    //Display states list
    if($rowCount > 0)
    {
        echo '<option value="">Select state</option>';
        while($row =  mysqli_fetch_array($query))
        { 
            echo '<option value="'.$row['sid'].'">'.$row['state'].'</option>';
        }
    }
    else
    {
        echo '<option value="">State not available</option>';
    }
}

if(isset($_POST["sid"]) && !empty($_POST["sid"]))
{
    //Get all city data
    $query = mysqli_query($con,"SELECT * FROM city WHERE sid =".$_POST['sid']."");

    //Count total number of rows
    $rowCount = mysqli_num_rows($query);

    //Display cities list
    if($rowCount > 0)
    {
        echo '<option value="">Select city</option>';
        while($row = mysqli_fetch_array($query))
        { 
            echo '<option value="'.$row['cid'].'">'.$row['city'].'</option>';
        }
    }
    else
    {
        echo '<option value="">City not available</option>';
    }
}
?>

填充下拉列表 - PHP Ajax MySQL

5 个答案:

eg1.html

getDropdownOptions.php