How do I bulk delete questions

Question

Let's say there 'sa 30- question in my hand. I would like to delete these 30 questions at a time. But there are some coding errors and much appreciated if you could help me

public function Clear()
    {
        $stmt = $this->db->prepare("SELECT id FROM ask_data WHERE standart=0");
        $stmt->execute();

        if ($stmt->rowCount() > 0)
        {
            $ask_cnt = $stmt->rowCount();

            $ask_data = array();

            while ($row = $stmt->fetch())
            {
                $data = array("ask_id" => $row['id']);
                $stmt2 = $this->db->prepare("DELETE FROM  id FROM questions WHERE ask_id=(:ask_id)");
                $stmt->bindParam(':ask_id', $ask_data[$i], PDO::PARAM_INT);
                $stmt2->execute();  
            }
            $i = 0;
            $count = count($ask_id);

            for ($i=0;$i<$count;$i++)
            {
                $data = array("ask_id" => $row['id']);
                $stmt2 = $this->db->prepare("DELETE FROM  id FROM questions WHERE ask_id=(:ask_id)");
                $stmt->bindParam(':ask_id', $ask_data[$i], PDO::PARAM_INT);
                $stmt2->execute();
            }
        }
    }

Answer 1

The delete statement is wrong - you have two from clauses. You should remove the FROM id :

DELETE FROM questions WHERE ask_id=(:ask_id)

Having said that, you could dramatically simplify your program by using the IN operator instead of a separate query:

DELETE FROM questions
WHERE ask_id IN (SELECT id 
                 FROM   ask_data
                 WHERE  standart = 0)

Answer 2

hy,Your delete query is not correct.You can use it like

"DELETE FROM questions WHERE ask_id=".$row['id'].";

Answer 3

I'm not understanding why you need a loops in your code to run thirty separate DELETE statement.

If the goal is delete rows from the questions table which have an ask_id column value that matches an id value from ask_data where the standart column has a value of zero...

this could be done in one SQL statement. One database roundtrip. No need for a separate SELECT statement, fetching rows, and running through a loop to perform more SQL statements.

  DELETE q.*
    FROM ask_data d
    JOIN questions q
      ON q.ask_id = d.id
   WHERE d.standart=0