除了在OOP方法中使用foreach之外，如何从数据库中获取数据？

I'm using PDO to connect the database and using OOP method in coding

this is how to get the posts and comments

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;
        }
    }
}

and this how to call the functions and display posts and comments

<?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;
            }
        }
    }
}
?>

But sadly I always get error -> Fatal error: Maximum execution time of 30 seconds exceeded in C:\xampp\htdocs\RIO\RIO\RAI\session_rai\includes\db.php on line 14

So, Any solutions for this case? Thanks.

Your class structure is wrong.

1. You don't need DBConnector class
2. Never create more than one connection to database with same credentials
3. Most of code in MyWeb class is useless too

So, create a PDO connection, then instantiate MyWeb class and then get your data

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();
    }
}    

same with output

<?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
if you make selectArray function this way

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

you can save yourself a line or two:

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);
}

You have a syntax error here

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

While it should be

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