PHP查詢從1和表2個字段

Question

我有一個數據庫表（furcodes）與字段A，B，C，d，E 我使用此代碼來創建一個Joomla網站兌換代碼系統：

<?php 
$redeem_code = JRequest::getString('redeem_code', '', 'post'); 
$db =& JFactory::getDBO(); 
$query = " 
    SELECT COUNT(`B`) 
     FROM `furcodes` 
     WHERE `B` = '$redeem_code' ; 
"; 
$db->setQuery($query); 
$count = $db->loadResult(); 
if ($count) { 

    $mainframe =& JFactory::getApplication(); 
    $mainframe->enqueuemessage('You have succesfully redeemed this fur code'); 
    return false; 
} else { 
    $mainframe =& JFactory::getApplication(); 
    $mainframe->enqueueMessage(JText::_('Invalid code. Please check and try again.'), 'error'); 
    return false; 
} 
?> 

我使用計數來檢查這個代碼是否存在於數據庫中，但是我還需要從列「E」中得到表示這個代碼是否曾經使用過的字段（值0 =未使用或使用1 = ，每個代碼一個使用），並創建一個如果是這樣的：

if $used == 1 
echo "This code has been used" 

任何幫助嗎？

---

我使用的最終代碼，它可能會幫助別人。

<?php 
$your_fur_code = JRequest::getString('fur_code', '', 'post'); 
$db =& JFactory::getDBO(); 
$query = "SELECT `E` FROM `furcodes` WHERE `B` = '$your_fur_code'"; 
$db->setQuery($query); 
$code_used = $db->loadResult(); 
if ($code_used == "1") { 
    $mainframe =& JFactory::getApplication(); 
    $mainframe->enqueueMessage(JText::_('The code has already been used.'), 'error'); 
    return false; 
} if ($code_used == "0") { 
    $mainframe =& JFactory::getApplication(); 
    $mainframe->enqueuemessage('You have succesfully redeemed this code'); 
    return false; 
} else { 
    $mainframe =& JFactory::getApplication(); 
    $mainframe->enqueueMessage(JText::_('Invalid code. Please check and try again.'), 'error'); 
    return false; 
} 
?> 

Answer 1

沒有必要檢查計數可言，只是做一個常規選擇的E列

SELECT `E` FROM `furcodes` WHERE `B` = '$redeem_code' 

如果沒有行被返回，你知道代碼不存在噸表中。如果返回一行，則可以檢查E的返回值以查看狀態。

Answer 2

變化

$query = "SELECT COUNT(`B`) FROM `furcodes` WHERE `B` = '$redeem_code' ;"; 

TO

$query = "SELECT COUNT(`B`) FROM `furcodes` WHERE `B` = '$redeem_code'";