$dbh->do("CREATE TABLE IF NOT EXISTS `test` ( `string` VARCHAR(256))"
+);

 my $string = '/a/b/c/d';

 my $I = qq{ INSERT INTO `test` (`string`) VALUES (?) }; 
 my $sI = $dbh->prepare($I);
 $sI->execute($string);

 my $R1 =  qq{ SELECT * FROM `test`};
 my $sR1 = $dbh->prepare($R1);
 my $row1 = $sR1->execute();
 say "total1: $row1";
 while( my $L1 = $sR1->fetchrow_hashref )
    {
     say "$L1->{'string'}";
    }

 my $R2 =  qq{ SELECT * FROM `test` WHERE `string`=?};
 my $sR2 = $dbh->prepare($R2);
 my $row2 = $sR2->execute();
 say "total2: $row2";
 while( my $L2 = $sR2->fetchrow_hashref )
        {
         say "$L2->{'string'}";
        }
[download]

total1: 1
/a/b/c/d
total2: 0E0
[download]