function del(id){
  $.ajax({
    url:'../Controllers/actions.php',
    type:'POST',
    data:'code='+id+'&boton=delete_product'
  }).done(function(ans){
    alert(ans);
  });
 
}
 
 

case 'delete_product':
					$code   = $_POST['code'];
					$delete = new product();
					if($delete->delete($code)){
						echo "success";
					}
					else{
						echo "there is something wrong";
					}
				break;
 

function delete($code){
			$sql = "DELETE FROM product WHERE id_product='$code'";
			if($this->conexion->conexion->query($sql)){
				return true;
			}
			else{
				return false;
			}
			$this->conexion->cerrar();
		}
 
		 function show_product(){
			$sql = "SELECT * FROM product";
			$record = $this->conexion->conexion->query($sql);
			$item =0;
 
			if(!$this->conexion->conexion->query($sql)){
				printf("Errormessage: %s\n", $this->conexion->conexion->error);
			}
			if($record->num_rows>0){
				while($show = $record->fetch_array(MYSQLI_ASSOC)){
					$item += 1;
					echo '<tr>
								<td>'.$item.'</td>
								<td>'.$show["code"].'</td>
								<td>'.$show["product"].'</td>
								<td>'.$show["price"].'</td>
								<td>'.$show["stock"].'</td>
								<td><button class="btn btn-danger" onclick="del('.$show["code"].');"><span class="glyphicon glyphicon-trash"></span></button></td>
						 </tr>';
				}
				//this is for counting number of page
 
			}
			else{
					echo '<tr><td colspan="7">no hay registros</td></tr>';
			}
		}
 

	$sql = "DELETE FROM product WHERE id_product='$code'";
<td><button class="btn btn-danger" onclick="del('.$show["id_product"].');"><span class="glyphicon glyphicon-trash"></span></button></td>