我如何在我的 php 代码中创建删除功能

Question

I have school order. I need to create a delete function on a application that they made. I dont know how to make this at the moment. I know how to make a CRUD system in laravel, but this is plain PHP.

 private function add() 
 {    $klantId = -1;
      if (isset($_POST['inputklanten'])) 
      {
           $klantId = $_POST['inputklanten'];
      }
      $row = $this->getKlantVars($klantId); 
      $rowreservering = $this->getReserveringVars(-1);
      $row = array_merge($row, $rowreservering);

      $output = "
           <form action='?action=add' method='post' enctype='multipart/form-data'>

                <label>Selecteer klant
                </label>

                <select id='inputklanten' name='inputklanten'>" .
                     $this->getKlanten() . "                         
                </select> 

                <input type='submit' name='submit_klantselecteren' 
                       id='submit_klantselecteren' value='Selecteer klant'/>
      </form>" .

      $this->showReserveringForm($row);

      return $output;   
 }

 protected function edit()
 {
      $reserveringId = -1;
      if (isset($_GET['reservering'])) 
      {
           $reserveringId = $_GET['reservering'];
      }

      $row = $this->getReserveringVars($reserveringId); 
      $klantId = $row['klant_id'];
      $rowklant = $this->getKlantVars($klantId); 
      $row = array_merge($row, $rowklant);

      $output = $this->showReserveringForm($row);

      return $output;
 }

Above here you can see an edit and add functions they made. I hope someone can help me out with this problem.

At the moment this is my delete function. It works and shows the echo when I'm clicking on the delete button with the id in the url

     protected function delete() 
 {
      $output = "delete gevonden";
      return $output;
 }

Answer 1

    protected function delete()
{
    $reserveringId = -1;
    if (isset($_GET['reservering']))
    {
        $reserveringId = $_GET['reservering'];
    }

    // sql to delete a record
    $sql = ("DELETE FROM `reservering` WHERE `reservering`.`reservering_id` = '$reserveringId';");

    if ($this->connection->query($sql)) {
        $output = "Reservering is succesvol verwijderd";
        return $output;
    } else {
        $output = "Het is niet gelukt om de reservering te verwijderen";
        return $output;
    }
}

I did it peeps thanks for helping :)

Answer 2

Example function, but you have to learn.

function delete_products($id) {
    global $db;


    $sql = "DELETE FROM products ";
    $sql .= "WHERE id='" . db_escape($db, $id) . "' ";
    $sql .= "LIMIT 1";
    $result = mysqli_query($db, $sql);

    // For DELETE statements, $result is true/false
    if($result) {
      return true;
    } else {
      // DELETE failed
      echo mysqli_error($db);
      db_disconnect($db);
      exit;
    }
  }

OO

  public function delete() {
    $sql = "DELETE FROM " . static::$table_name . " ";
    $sql .= "WHERE id='" . self::$database->escape_string($this->id) . "' ";
    $sql .= "LIMIT 1";
    $result = self::$database->query($sql);
    return $result;