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PHP中的从属下拉列表来自数据库的同一个表
EN

Stack Overflow用户
提问于 2017-02-07 19:27:58
回答 1查看 8.5K关注 0票数 2

我需要做一些下拉列表。在这里,从第一个下拉列表中,每当我在第二个下拉列表的选项中选择 Region 时,它应该会显示所选区域的相应Country。但在选择一个区域后,第二个下拉列表不会显示任何内容。我寻找了解决方案,但没有找到合适的解决方案,因为我只为数据库的一个表执行了所有这些操作。

数据库

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";

CREATE TABLE `geo` (
  `Region` varchar(200) NOT NULL,
  `Country` varchar(200) NOT NULL,
  `City` varchar(200) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

INSERT INTO `geo` (`Region`, `Country`, `City`) VALUES
('Asia', 'Bangladesh', 'Dhaka'),
('Europe', 'France', 'Paris'),
('Asia', 'Bangladesh', 'Khulna'),
('Europe', 'France', 'Avignon'),
('Europe', 'Spain', 'Barcelona'),
('Europe', 'Spain', 'Madrid'),
('Asia', 'Srilanka', 'Colombo');

数据库连接,php

<?php
error_reporting( ~E_DEPRECATED & ~E_NOTICE );

define('DBHOST', 'localhost');
define('DBUSER', 'root');
define('DBPASS', '');
define('DBNAME', 'ddl');

$conn = mysql_connect(DBHOST,DBUSER,DBPASS);
$dbcon = mysql_select_db(DBNAME);

if ( !$conn ) {
    die("Connection failed : " . mysql_error());
}

if ( !$dbcon ) {
    die("Database Connection failed : " . mysql_error());
}

?>

index.php

<?php
require_once 'dbconnect.php';

$query ="SELECT * FROM geo";
$results = mysql_query($query);
?>
<!DOCTYPE html>
<html>
<head>
<title>DDL - Select</title>
</head><?php 
        $bul[10000007] = false;
    ?>

<style>
body{width:610px;}
.frmDronpDown {border: 1px solid #F0F0F0;background-color:#C8EEFD;margin: 2px       0px;padding:40px;}
.demoInputBox {padding: 10px;border: #F0F0F0 1px solid;border-radius:  4px;background-color: #FFF;width: 50%;}
.row{padding-bottom:15px;}
</style>
<script src="https://code.jquery.com/jquery-2.1.1.min.js"   type="text/javascript"></script>
<script>
function getCountry(val) {
$.ajax({
    type: "POST",
    url: "get_country.php",
    data:'region_id='+val,

   success: function(data){
    $("#country-list").html(data);
  }
  });
  }

  function selectRegion(val) {
  $("#search-box").val(val); 
  $("#suggesstion-box").hide();
  }
  </script>

 <body>
<div class="frmDronpDown">
<div class="row">

<form>
<label>Region: </label>
<select name="region" id="region-list" class="demoInputBox"      onChange="getCountry(this.value);">
    <option value="">Select Region</option>

        <?php

        $sql = "SELECT * FROM geo";
        $res = mysql_query($sql);
        while($row = mysql_fetch_assoc($res)) {

            if($bul[$row['Region']] != true && $row['Region'] != 'Region'){
            ?>
                <option value="<?php echo $row['Region']; ?>"><?php echo   $row['Region']; ?></option>
        <?php   
                $bul[$row['Region']] = true;
            }
        } 
        ?>

    </select>
</div>


<div class="row">
    <label>Country: </label>
    <select name="country" id="country-list" class="demoInputBox">
        <option value="">Select Country</option>
    </select>   


</form>

</div>
</div>

</body>
</html>

get_country.php

<?php
    require_once 'dbconnect.php';


    if(!empty($_REQUEST["region_id"])) {

    $query ="SELECT * FROM geo WHERE Region =" . $_POST["region_id"];
    $result = mysql_query($query);
?>
    <option value="">Select Country</option>

<?php
    while($row2=mysql_fetch_assoc($result)){
        if($bul2[$row2['Country']] != true && $row2['Country'] != 'Country')        { ?>
            <option value="<?php echo $row['Country']; ?>"><?php echo     $row['Country']; ?>  </option>
 <?php  
         $bul2[$row2['Country']] = true;
         }
     }
    }
?>
EN

回答 1

Stack Overflow用户

回答已采纳

发布于 2017-02-07 20:23:13

使用mysqli函数而不是mysql函数。还可以使用mysqli_escape_string()函数来防止sql注入。

在get_country.php文件中,您错过了$_POST"region_id“前后的'

$query ="SELECT * FROM geo WHERE Region =" . "'" . mysqli_escape_string($conn, $_POST["region_id"] ) ."'";

而且你还需要在$row['Country']中修复,它应该是$row2'Country‘。

以下是我的机器上的工作代码:

index.php

<?php
require_once 'dbconnect.php';
$query   = "SELECT * FROM geo";
$results = mysqli_query($conn, $query);
?>
<!DOCTYPE html>
<html>
<head>
<title>DDL - Select</title>
</head><?php
$bul[10000007] = false;
?>

<style>
body{width:610px;}
.frmDronpDown {border: 1px solid #F0F0F0;background-color:#C8EEFD;margin: 2px       0px;padding:40px;}
.demoInputBox {padding: 10px;border: #F0F0F0 1px solid;border-radius:  4px;background-color: #FFF;width: 50%;}
.row{padding-bottom:15px;}
</style>
<script src="https://code.jquery.com/jquery-2.1.1.min.js"   type="text/javascript"></script>
<script>
function getCountry(val) {
$.ajax({
    type: "POST",
    url: "get_country.php",
    data:'region_id='+val,

   success: function(data){
    $("#country-list").html(data);
  }
  });
  }

  function selectRegion(val) {
  $("#search-box").val(val); 
  $("#suggesstion-box").hide();
  }
  </script>

 <body>
<div class="frmDronpDown">
<div class="row">

<form>
<label>Region: </label>
<select name="region" id="region-list" class="demoInputBox"      onChange="getCountry(this.value);">
    <option value="">Select Region</option>

        <?php
$sql = "SELECT * FROM geo";
$res = mysqli_query($conn, $sql);
while ($row = mysqli_fetch_assoc($res)) {
    if ($bul[$row['Region']] != true && $row['Region'] != 'Region') {
?>
               <option value="<?php
        echo $row['Region'];
?>"><?php
        echo $row['Region'];
?></option>
        <?php
        $bul[$row['Region']] = true;
    }
}
?>

    </select>
</div>

<div class="row">
    <label>Country: </label>
    <select name="country" id="country-list" class="demoInputBox">
        <option value="">Select Country</option>
    </select>   

</form>
</div>
</div>
</body>
</html>

get_country.php

<?php
    require_once 'dbconnect.php';


    if(!empty($_REQUEST["region_id"])) {

    $query ="SELECT * FROM geo WHERE Region =" . "'" . mysqli_escape_string($conn, $_POST["region_id"] ) ."'";
    //echo $query ="SELECT * FROM geo WHERE Region =" . "'" . $_POST["region_id"] ."'";

    $result = mysqli_query($conn, $query);
?>
    <option value="">Select Country</option>

<?php
    while($row2=mysqli_fetch_assoc($result)){

        //var_dump($row2);
        if($bul2[$row2['Country']] != true && $row2['Country'] != 'Country' || 1)        { ?>
            <option value="<?php echo $row2['Country']; ?>"><?php echo     $row2['Country']; ?>  </option>
 <?php  
         $bul2[$row2['Country']] = true;
         }
     }
    }
?>

和dbconnect.php

<?php
error_reporting( ~E_DEPRECATED & ~E_NOTICE );

define('DBHOST', 'localhost');
define('DBUSER', 'root');
define('DBPASS', '');
define('DBNAME', 'ddl');

$conn = mysqli_connect(DBHOST,DBUSER,DBPASS);
$dbcon = mysqli_select_db($conn, DBNAME);

if ( !$conn ) {
    die("Connection failed : " . mysqli_error());
}

if ( !$dbcon ) {
    die("Database Connection failed : " . mysqli_error());
}

?>
票数 2
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/42088706

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