Define use...

Then you probably want to interact with the database in any way: use DBI

Good try...

Aha, question updated with some real code, let's see...

looks like a work for a hash... my @sku = ('NUMBER') is not what you want probably; first of all because @ mean a list of elements, not a single number, and also because a %hash is much better here. If you define @sku as an array you could have by mistake the same number for two products (and this is a BIG problem), but a hash will not permit you to do this. The number $sku is the key (unique) and the catalog ref is the value.

so the first thing that you should try to fix is these two lines.

my @sku = ('NUMBER');
for my $sku (@sku) {...
[download]

Instead connect to the database and prepare something like: select field2 for mytable where field1 = ? and fill the gap with the correct number sku with execute($sku). Read the manual of DBI for the details

finally when you have your hash you could write something like this