Generating CDKey works, checking if exists doesnt - php

Question

I have a problem with my code.
The first one works, it will generate a cdkey and enter it to the mysql db.
<?
function createRandomKey($amount)
{
$keyset = "abcdefghijklmABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
$randkey = "";
for ($i=0; $i<$amount; $i++)
$randkey .= substr($keyset, rand(0, strlen($keyset)-1), 1);
return $randkey;
}
if($_POST['post_true'] == "true")
{
$randomkey = createRandomKey(20);
query(" INSERT INTO cdkeys (`cdkey`,`used`,`user_id`) VALUES (' ".escapeadmin($randomkey)."', '".escapeadmin(0)."', '".escapeadmin(0)." ') ");
echo "<b>Generated Key:</b> ";
echo $randomkey;
}
?>
it will rand different numbers and characters, a-z0-9, the cdkey length is 20 chars.
the second code is the one for checking if the cdkey exists in the databse.
<?
// FETCH POSTED CDKEY
$postedkey = $_POST['cdkey'];
$sql_check_cdkey = query("SELECT * FROM cdkeys WHERE cdkey = '".escape($postedkey)."' ");
$qry_check_cdkey = mysql_fetch_array($sql_check_cdkey);
if(mysql_num_rows($sql_check_cdkey) == "0") { red("Wrong CD Key Entered"); echo $_POST['cdkey']; }
else
{
echo "exists, magic time";
}
?>
now the problem is, that whenever i enter the key , lets say:
736KhYDmZhm1G1P72Ja5HIUg4VcBd9
that is in the databse (i checked, and the generator even echo the key for me)
the key cannot be find. i always get cd key don't exists message.
the key is there, but it's just not finding it.
i tried to change the key from the numbers and characters to "testkey123" and when i tried to search, it worked this time.
it seems like it cant find it as random characters.
what am i missing? i really need to fix it.
thank you

Answer 1

Your test string '736KhYDmZhm1G1P72Ja5HIUg4VcBd9' is 30 characters long - but you say that "cdkey length is 20 chars". You are probably truncating the string when you store it.
Change the size of the column that stores the string:
ALTER TABLE tablename CHANGE cdkey cdkey varchar(100)