php - PDO 查询关联表并显示结果

Question

我是 PHP 新手，目前正在学习 PDO 并远离 MySQLi，我是 CMS 大学的学生，我正在学习这门类(class)，老师希望我关联两个表并显示它们，他的 MySQLi 代码看起来像这样

$query = "SELECT * FROM categories WHERE cat_id = {$post_category_id}";
$select_categories_id = mysqli_query($connection,$query);

while($row = mysqli_fetch_assoc($select_categories_id)) {
    $cat_id = $row['cat_id'];
    $cat_title = $row['cat_title'];
    echo "<td>{$cat_title}</td>";
}

我的 PDO 代码看起来像这样，它没有按应有的方式工作......

我之前在我的类(class)中做过几个 PDO 查询，但不知何故这不起作用。

$query = "SELECT * FROM categories WHERE cat_id = :post_category_id";
$result = $connection->prepare($query);
$result->execute(array(":post_category_id"=>$post_category_id));
while($row=$result->fetch(PDO::FETCH_ASSOC)){
    extract($row);
    $cat_id = $row['cat_id'];
    $cat_title = $row['cat_title'];
    echo "<td>$cat_title</td>";
}

我将不胜感激任何和所有的建议

Answer 1

如果您设置正确的连接数据库。它工作正常

  $query = "SELECT * FROM categories WHERE cat_id = :post_category_id";
  $result = $connection->prepare($query);
  $result->bindParam(':post_category_id',$post_category_id, PDO::PARAM_INT);
  $result->execute();
  $result = $result->fetchAll(PDO::FETCH_ASSOC);
      if ($result) {
         foreach($result as $row){
            $cat_id = $row['cat_id'];
            $cat_title = $row['cat_title'];
            echo "<td>".$cat_title."</td>";
          }
       }