來自mysql的下拉列表的值

Question

我試圖編寫一個估計公式，並且用填充的下拉列表的值填充了MySQL。

這個公式的想法是，當用戶從下拉列表中選擇一個服務，並將數量放入文本字​​段時，程序將計算服務的價格。

從MySQL表中選擇獎品的價值。

$query="SELECT $con_tent FROM services WHERE $id; 
$con_tent= 'price'. '*'. $qunatity 

但我不知道如何從dropdwon列表中獲取值。

大概用了Ajax但還不知道如何。

我解決了這個由modyfing代碼http://www.9lessons.info/2010/08/dynamic-dependent-select-box-using.html

<?php 
    require_once 'login.php'; 
    $db_server = mysql_connect($db_hostname, $db_user, $db_password); 
    mysql_select_db($db_database) or die("unable to select database:" . mysql_error()); 

    echo "<form action=licz.php method='post'>"; 
    echo " <label for=\"select\"><select name=\"\" value=\"Select\" size=\"1\">"; 

    $query = "SELECT * FROM uslugi ORDER BY id ASC"; 
    $result = mysql_query($query); 
    while ($row = mysql_fetch_array($result)) { 
     global $ff; 

     $ajdi = $row['id']; 

     $nazwa = $row['nazwa']; 
     $options.= "<option value=\"$ajdi\" name=\"oko\">" . $nazwa . $ajdi; 
    } 
    echo "<option>"; 
    echo $options; 

    echo "</option></select>"; 
    echo " <input type=\"submit\" name=\"Submit\" value=\"Submit\">"; 

    echo "</form>"; 
    function wybor() { 
     global $id; 
     global $con_tent; 
     $var = 'price' . '*'; 
     $quantity = 3; 
     //quantity will by from textfield but now it constant 
     $id_value = 1; 
     // here i need to make it dynamic 
     $id = "id={$id_value}"; 
     $con_tent = $var . $quantity; 
    } 

    echo wybor(); 

    $query = "SELECT $con_tent FROM services WHERE $id"; 
    //query 

    if (!$query) Die("Unable to query: " . mysql_error()); 

    $result = mysql_query($query); 

    if (!$result) Die("Unable to query: " . mysql_error()); 
    $rows = mysql_num_rows($result); 
    for ($a = 0; $a < $rows; ++$a) { 
     $row = mysql_fetch_row($result); 

     echo $row[0] . " "; 
     echo $row[1] . " "; 
     echo $row[2] . " "; 
     echo $row[3] . "$br"; 
    } 


?> 

Answer 1

您應該應用Ajax調用以獲取數據庫值時，有通過調用平變化事件的JavaScript函數在選擇框的變化。

更多的jQuery AJAX

http://www.sitepoint.com/ajax-jquery/

http://www.tutorialspoint.com/jquery/jquery-ajax.htm