It just does not print the @Geo_areas after it should be full with the content of the select statement.

<not_entirely_tongue_in_cheek> Of course not, as there is no print statement in the code you showed us :p </not_entirely_tongue_in_cheek>

My guess is that your $Special_data_retrieval variable isn't correctly formed, and so your query is returning zero rows. Try adding a print "$Select_areas\n"; before the query is executed, and then test it manually.

Also, be aware that selectrow_array fetchrow_array will only give you a single row of data. So if you are expecting multiple rows then it would generally be contained within a while loop. Yes, I know you mentioned a while loop in your original post, but you indicated that the whole code snippet is within a while loop. And that isn't what I mean. What you probably need is something like this:

while (my @row = $sth_Geo->fetchrow_array) {
    print "@row\n"; # Or whatever
}
[download]

If you want to grab the whole lot in one go, then you probably want to use selectall_arrayref fetchall_arrayref

Cheers,
Darren :)