I usually accumulate info in a fetchrow while loop, it is easier for me conceptually to work with the data row by row: 
...  
$sth->execute;
my (%rows,%cols,$rtime,$dev,$value);
while (($rtime,$dev,$value)=$sth->fetchrow) {
   $rows{$rtime}{$dev}=$value;
   $cols{$dev}++;
}
$sth->finish if $sth->{Active};  # really don't need finish if you got
+ all the data
# now column headers can be computed
my @cols=sort keys %cols;
map { $cols{$cols[$_]}=$_+1 } 0..$#cols;  # get indexes
my @headers=('RTIME',sort keys %cols);
my @row;
print join("\t",@headers),"\n";
# and rows can be extracted (empty cells where a dev wasn't seen for a
+ particular rtime)
for $rtime (sort keys %rows) {
   $row[0]=$rtime;
   map { $row[$cols{$_}]=$rows{$rtime}{$_} } keys %{$rows{$rtime}}; 
   print join("\t",@row),"\n";
}

[download]
You would need to plug the data into HTML::Template, that I'm not as familiar with but it doesn't look hard.

HTH,
SSF

In reply to Re: Creating list of hashes within a list of hashes (DBI and HTML::Template) by sflitman
in thread Creating list of hashes within a list of hashes (DBI and HTML::Template) by 1Nf3

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