Strange loop output

packetstormer has asked for the wisdom of the Perl Monks concerning the following question:

I having been looking at this for a while and I can't figure out why its happening (I am still a newbie BTW!). Here is a snippet of the code. I am using strict params too.

The problem is that, near the end, in the while($query_handle->fetch()) part. If I print the the $get_file I get a list of each row as planned. However, if I push that string into the array and then print the array I get a really long list of duplicate entries!

.......
my $dsn = "dbi:$platform:$database:$host:$port";
my $connect = DBI->connect($dsn, $user, $pw);

foreach my $k(@shows_array) {
    my($show_id,$title,$next_episode) = split(/\|/,$k);
        
my $query = "SELECT count(episode) from shows where episode = \"$next_
+episode\"";

my $query_handle = $connect->prepare($query);

$query_handle->execute();

$query_handle->bind_columns(\$episode); {
            if($episode eq "0") {
            $get_file = "$url$title"." "."$next_episode"."&catid=$cati
+d"."&num=".$num."&age="."$age"."&username=".$username."&".$apikey;
            #print "<br />".$get_file."<br />";
                        #THE PRINT ABOVE OUTPUTS FINE
            push(@nzb_list,$get_file);
            print @nzb_list;
            #THE PRINT ABOVE IS THE PROBLEM
                        };
            
   }
}
[download]

Can anyone see my mistake?

Comment on Strange loop output Select or Download Code

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Re: Strange loop output by wind (Priest) on Apr 21, 2011 at 08:10 UTC
Don't print your array within the loop. Instead wait until you're loop is finished before printing it. Otherwise, you'll just get each subsequent build on the @array showing the duplicate items On a side note, add error checking to your database connect and the execution of your statement handle. Also if you use placeholders, you can prepare your statement handle just once my $dsn = "dbi:$platform:$database:$host:$port"; my $connect = DBI->connect($dsn, $user, $pw) or die "DB connect failed: $DBI::errstr"; my $query_handle = $connect->prepare(q{SELECT count(episode) from show +s where episode=?}); foreach my $k (@shows_array) { my ($show_id, $title, $next_episode) = split /\\|/, $k; $query_handle->execute($next_episode) or die $connect->errstr; $query_handle->bind_columns(\my $episode); if($episode eq "0") { my $get_file = "$url$title $next_episode&catid=$catid&num=$num +&age=$age&username=$username&$apikey"; push @nzb_list, $get_file; } } print @nzb_list; [download]	[reply] [d/l]
Re^2: Strange loop output by packetstormer (Monk) on Apr 21, 2011 at 08:13 UTC
It doesn't seem to matter where I print. I just took it out of the loop and the same problem occurs!	[reply]
Re^3: Strange loop output by packetstormer (Monk) on Apr 21, 2011 at 08:18 UTC
Actually - it does matter where I print it! Moving it outside the loop makes it work correctly - thanks. I didn't know, and still don't, how that makes a difference!	[reply]
Re^4: Strange loop output by moritz (Cardinal) on Apr 21, 2011 at 08:30 UTC