#!/usr/bin/perl
use DBI;
tdbh = DBI->connect("DBI:CS­V:")
        or die "Cannot connect: " . $DBI::errstr;
my $sth = $tdbh->prepare("sele­ct * from ofphl");
$sth->execute();
my %dbi;
my $rec;
while(  $rec= $sth->fetch()  ) {
    $dbi{$rec->{id_field_name}}++;
};
open FILE, "< file.csv"
    or  die "Can't read file.csv: $!\n";
my $has= 1;
$|= 1;
while(  <FILE>  ) {
    my $id= ( split(/,/) )[0]; # Assuming ID is first field;
    if(  !$has != !$dbi{$id}  ) {
        print "DBI ", ( $has ? "stopped" : "started" ),
            " at record $id.\n";
        $has= !$has;
    }
}