Query database for current price and update FHEM accordingly

check.pl

#!/usr/bin/perl -l

use strict;
use warnings;
use DBI;
use Net::Telnet;
my $dbName="electricity";
my $dbUser="********";
my $dbPass="********";
my $dbHost="127.0.0.1";
my $dbPort=3306;
my $fhemHost="127.0.0.1";
my $fhemPort=7072;
my $fhemDummy="negElecPrice";

my $dbh = DBI->connect("DBI:mysql:database=$dbName;host=$dbHost;port=$dbPort",
                       $dbUser, $dbPass,
                       {'RaiseError' => 1});
my $query = "SELECT marketPrice FROM prices WHERE fromDate = DATE_FORMAT(NOW(),'%Y-%m-%d %H:00:00') AND marketPrice<0;";my $sth = $dbh->prepare($query);
$sth->execute();
my $row = $sth->fetchrow_hashref;
my $priceisnormal = 1;
my $telnet = new Net::Telnet (
    Timeout=>10,
    Port=>$fhemPort,
);
$telnet->open($fhemHost);

while ($row) {
  $priceisnormal = 0;
  $telnet->print("set $fhemDummy on");
  $row = $sth->fetchrow_hashref;
}
if ($priceisnormal) {
  $telnet->print("set $fhemDummy off");
}
$telnet->print('quit');
$telnet->close;
$sth->finish();
$dbh->disconnect();