Mysql更新命令失败

Question

令人难以置信的是，我有一个确切的脚本，其中有一个不同于“additional”的变量。但是，即使有一个额外的MySQL列，我无法得到它的更新。我甚至尝试改变其他东西，但它无法与此专栏一起工作。什么是冲突？

<?php 
echo "yup"; 
$lt2 = "yup"; 
$blah = "yup"; 
$username = "yup"; 
$lt1 = "yup"; 
$dbh = new PDO(censored); 
$sql = "UPDATE purchases SET additional = ? WHERE username = ? AND blah = ? AND kusername = ?"; 
$q = $dbh->prepare($sql); 
$params = array($lt1, $lt2, $username, $blah); 
$q->execute($params); 
$doc = new DOMDocument(); 
$r = $doc->createElement("location"); 
$doc->appendChild($r); 
foreach ($q->fetchAll() as $row) { 
    $e = $doc->createElement("location"); 
    $e->setAttribute('name', $row['additional']); 


    $r->appendChild($e); 

} 
print $doc->saveXML(); 

echo "work"; 
?> 

Answer 1

尝试

$sql = "UPDATE purchases SET additional = ? WHERE username = ? AND blah = ? AND kusername = ?"; 
$q = $dbh->prepare($sql); 
$params = array($lt1,$lt2, $username, $blah); 

Answer 2

能否请你告诉我这个表中有 “自动递增” ID与否。

如果是，请传递您已更新记录的ID。

$sql = "UPDATE purchases SET additional = '$lt1' WHERE purchase_id = ?"; 

如果没有，请更改查询是这样的：

$sql = "UPDATE purchases SET additional = '$lt1' WHERE username = ? OR blah = ? OR kusername = ?";