PHP PDO I can’t insert the numbers

I am new with php. I am trying to do a little game.

My purpose is , php will pick 5 number with rand function , and that numbers will add database.

I will show that numbers in index.php
Example :
Today : 1 , 23 , 24 , 31 , 45
Yesterday : 3 , 5, 12 , 31 , 34

but i can’t insert the numbers into the db.

Here is the code and database ;

<?php
include 'config.php';
$ayarsor=$db->prepare("select * from bet where lot_id=?");
$ayarsor->execute(array(0));
$ayarcek=$ayarsor->fetch(PDO::FETCH_ASSOC);



$lot_1 = rand(1,35);
$lot_2 = rand(1,35);
$lot_3 = rand(1,35);
$lot_4 = rand(1,35);
$lot_5 = rand(1,35);

echo $lot_1;
echo $lot_2;
echo $lot_3;
echo $lot_4;
echo $lot_5;


   $ekle = exec("INSERT INTO bet (lot_1,lot_2) VALUES ('$lot_1','$lot_2')");


?> 

This is my database ;
http://prntscr.com/eav1td


Source: stackoverflow-php