Help with num_rows

[EchoFool]

I have two tables which have simple terms this:

 

Item ID  | User ID  | Quantity

  1              1          200

 

And the other has:

 

Item ID  | TradeAllowed |

  1                1

 

With a query like this:

$GetItems = mysql_query("SELECT useritem.ItemID,useritem.Quantity FROM useritem,item WHERE useritem.UserID='{$_SESSION['Current_User']}' AND useritem.Quantity > 0 AND item.Trade='1'")
			Or die(mysql_error());

 

But for some reason say the user has the item. and the item does exist in both tables which it should. When i echo mysql_num_rows($GetItems); it echo's 3. No idea where it gets 3 from. If anything 2 would make sense but it should only load one.

 

Why does it display 3?

[Barand]

Because you don't specify that the table should be joined on itemID, so it joins each record in one tablewith each record in the other.

 

<?php
$GetItems = mysql_query("SELECT useritem.ItemID,useritem.Quantity 
            FROM useritem
                INNER JOIN item ON useritem.itemID = item.itemID
            WHERE useritem.UserID='{$_SESSION['Current_User']}' 
            AND useritem.Quantity > 0 
            AND item.Trade='1'")  or die(mysql_error());
?>

[EchoFool]

Oh i see you have to tell it where the link is. Ok thankyou! How do i topic solve?