perlquestion
chefchanyu
Hi:
How can I separate the undef data and NULL data?
the following code work ok for undef/null data but Iwon't know which one is undef and which is null they all print out " ".
<code>
use strict;
use DBI;
use Data::Dumper;
my $dbh =
DBI->connect("dBi:mysql:cacti:localhost",
"cacti",
"cacti")
or die("Cannot connect: $DBI::errstr\n");
my $sth = $dbh->prepare("select * from data_template_data");
$sth->execute;
my $names = $sth->{NAME};
for (@$names)
{
printf("%-10s",$_);
}
print "\n";
while (my $row_ref = $sth->fetch())
{
for (@$row_ref)
{
if (defined($_))
{
printf("%-10s",$_);
}
# elsif ($_ eq '')
# {
# print 'NULL';
# }
elsif (undef($_))
{
print "\' \'";
}
}
print "\n";
}
</code>