use strict;
use warnings;

use DBI;
my $dbh = DBI->connect( 'DBI:mysql:test', 'foo', 'bar' ) or die;
my $lon = -0.232323127347249;
my $sql = qq| SELECT lon,lat,location_id FROM lat_long WHERE lon>= $lon|;
my $sth = $dbh->prepare($sql);
$sth->execute();
print STDERR "Rows not using placeholders ".$sth->rows."\n";

$sql = qq| SELECT lon,lat,location_id FROM lat_long WHERE lon >= ?|;
$sth = $dbh->prepare($sql);
$sth->execute($lon);
print STDERR "Rows using placeholders ".$sth->rows."\n";
__END__