SELECT intersect problem

[ninedoors]

Is there anything wrong with this query?

 

I have two tables one named 'currentlocations' and the other named 'frcstqunt'.  They both have a column named sku.  Is this the correct way to select only the sku's from currentlocations that are also in frcstqunt? 

 

<?php
//get matching skus from currentlocations
$query = "SELECT currentlocations.sku FROM currentlocations WHERE currentlocations.sku = frcstqunt.sku";
$result = mysql_query($query);
while ($row = mysql_fetch_assoc($result))
{
$arraycurrsku[] = $row['sku']; 
}
?>

 

I have checked the sku's in each table manually and there are exact matching skus that exist in both but I am return an empty array.  I would like to collect them all in an array for use.  Any thoughts?

[soycharliente]

Does this work better?

$query = "SELECT sku FROM currentlocations c JOIN frcstqunt f ON c.sku=f.sku";

[ninedoors]

Nope.

 

I get this error:

 

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in C:\xampp\htdocs\PTL\skudiff.php on line 49