Question

我使用PDO连接数据库并在编码中使用OOP方法

这是如何获取帖子和评论

class MyWeb{
public function SelectStatus($user_id){
        try{
            $DBC = new DBConnector();

            $query = "SELECT * FROM users U, posts P where P.user_id_fk=U.user_id and U.user_id=:user_id_fk";

            $params = array(":user_id_fk"=>$user_id);


            $result = $DBC->SelectArray($query,$params);

            if($result){
                return $result;
            } else throw new Exception("Post not selected!");
        }catch(Exception $e){
            echo "Caught Exception: ".$e->getMessage();
            return null;
        }
    }
public function SelectComment($post_id){
        try{
            $DBC = new DBConnector();

            $query = "SELECT * FROM comments C, users U WHERE C.user_id_fk = U.user_id and C.post_id_fk = :post_id_fk";


            $params = array(":post_id_fk"=>$post_id);

            $result = $DBC->SelectArray($query,$params);

            if($result){
                return $result;
            } else throw new Exception("Comment not selected!");
        }catch(Exception $e){
            echo "Caught Exception: ".$e->getMessage();
            return null;
        }
    }
}

以及如何调用这些功能并显示帖子和评论

<?php
        $NewStatus = $session->SelectStatus($user_id);

        if(!empty($NewStatus)){
            foreach($NewStatus as $data){
                $username = $data->username;
                $post = $data->post;
                $post_id = $data->post_id;
                                echo "".$username." | ".$post."";

                               $NewComment = $session->SelectComment($post_id);

                if(!empty($NewComment)){
                    foreach($NewComment as $cdata){
                        echo $cdata->comment;
            }
        }
    }
}
?>

但遗憾的是我总是得到错误 - ＆gt; 致命错误：第14行的C：\ xampp \ htdocs \ RIO \ RIO \ RAI \ session_rai \ includes \ db.php超出了30秒的最长执行时间

那么，这种情况的解决方案是什么？感谢。

Answer 1

您的语法错误

$query = "SELECT * FROM comments C, users U WHERE C.user_id_fk = U.user_id and C.post_id_fk = :post_id_fk";";

虽然应该

$query = "SELECT * FROM comments C, users U WHERE C.user_id_fk = U.user_id and C.post_id_fk = :post_id_fk";

Answer 2

你的班级结构错了。

您不需要DBConnector类
永远不要创建多个具有相同凭据的数据库连接
MyWeb类中的大多数代码也没用

因此，创建PDO连接，然后实例化MyWeb类，然后获取数据

class MyWeb{

    function __construct($dbc)
    {
        $this->dbc = $dbc;
    }

    public function SelectStatus($user_id)
    {
        $query = "SELECT * FROM users U, posts P 
                      WHERE P.user_id_fk=U.user_id and U.user_id=?";
        $stmt  = $this->dbc->prepare($query);
        $stmt->execute(array($user_id));
        return  $stmt->fetchAll();
    }

    public function SelectComment($post_id)
    {
        $query = "SELECT * FROM comments C, users U 
                      WHERE C.user_id_fk = U.user_id and C.post_id_fk = ?";
        $stmt  = $this->dbc->prepare($query);
        $stmt->execute(array($user_id));
        return  $stmt->fetchAll();
    }
}

与输出相同

<?php
$pdo = new PDO(... params);
$myweb = new MyWeb($pdo);
$NewStatus = $myweb->SelectStatus($user_id);
foreach($NewStatus as $row)
{
     echo $row['username']." | ".$row['post'];
     $NewComment = $myweb->SelectComment($post_id);
     foreach($NewComment as $cdata){
         echo $cdata['comment'];
    }
}

OR
如果你使selectArray以这种方式运作

public function selectArray()
{
    $args = func_get_args();
    $sql  = array_shift($args);
    $stmt  = $this->pdo->prepare($sql);
    $stmt->execute($args);
    return  $stmt->fetchAll();
}

你可以为自己保留一两行：

public function SelectStatus($user_id)
{
    $query = "SELECT * FROM users U, posts P 
                  WHERE P.user_id_fk=U.user_id and U.user_id=?";
    return  $this->dbc->selectArray($query, $user_id);
}

除了在OOP方法中使用foreach之外，如何从数据库中获取数据？

2 个答案: