更新查询不工作

Question

我试着写与PDO更新查询，但它不能正常工作

for ($count = 0; $count < 4; $count++) { 
     if (!trim($elements[$count])=='') { 

       $query = "update servers set " . '?' . "=" . '?' . "where " . '?' . "=" . '?'; 
       $pdo = new PDO($db->dsn, 'adp', 'pass'); 
       $stmt = $pdo->prepare($query); 
       $stmt->bindParam(1, $index[$count]); 
       $stmt->bindParam(2, $elements[$count]); 
       $stmt->bindParam(3, $index[$count]); 
       $stmt->bindParam(4, $ServerName); 
       $stmt->execute(); 
      } 
} 

Answer 1

表和列名不能在PDO参数来代替。有关更多详细信息，请参阅this answer。