call id of a table to a new table and insert values to this new table

[learner001]

I have recently started to write server scripts. Although the question may seem to be very basic but i am not able to get a solution.
I have two tables one is PRODUCTS and the other is DEALS

PRODUCTS TABLE:

Id  product_name  product_desc   category    brand
1   product1      desc1          cat1        brand1                                                     
2   product2      desc2          cat2        brand2

DEALS TABLE

Id     deal_name      productid    
1      todayoffer        2            

I wish to put the value of id (from PRODUCTS table) into productid and carry this value to DEALS table and then add deal_name along with it as shown above. The recent code that i am using is

<?
require_once('config.php'); //connection

$dealname=$_REQUEST['dealname'];
$productid=$_REQUEST['productid'];
$id=$_REQUEST['id'];
$productid=$_REQUEST['productid'];

$inserts = mysql_query("insert into deals (dealname,productid) values ('".$dealname."','".$productid."') SELECT productid FROM products WHERE productid = '".$id."'");

    $posts[0]['message'] = 'Deal Registered';
    $idd = mysql_insert_id();
    $selectt = mysql_query("select * from deals where id = '".$idd."'");

    $posts[0]['detail'] = $selectt;
    header('Content-type: application/json');
    echo json_encode($posts);
?>

I would really appreciate if anyone could guide me and tell me why i am not getting the result

[Traevel]

Well at first glance, in insert into deals (dealname,productid) you are using dealname and not deal_name. Also, where you are using SELECT productid FROM products WHERE productid = '".$id."'"); you are twice referring to a column productid while the table products only has id, according to your description of the table layout.

Also, it could be that you are passing $productid as text and not as a number because of the single quotes. Similar problem with $id and $idd (which you are also comparing to id instead of Id by the way).

You could try printing the results of mysql_query to see whether the query fails or not. If you have access to the database itself via a console or phpmyadmin for instance you could test the queries using some default values. That way you'll be sure the queries themselves are valid, and whether or not the column/table names are indeed correct, before debugging the code.