Do you mean DBD::DBM? To get help from the PerlMonks, you need to give some more details, so we don't have to guess about what the problem is.

Yes .... I have to execute a perl script(Unix/Windows) to update in SQL database. I have a limitation that, I can only use DBD::DBM to run the query. As i haven't worked with DBM files, I want to know how to execute with DBM Module. I have written a sample script, but i'm receiving error as \.Usr.lck : No such directory or file exist. DO i need to place the SQL files in some folder or Do i have to use it in some other way? Could you please elaborate me out.

#!/usr/bin/perl -w

use strict;
use DBI;
my $dbh=DBI->connect('dbi:DBM:f_dir=D:\Perl\site\lib\DBD\usr.sql')
    or die "Can't connect to $DBI::errstr";
                                                             
my $sql = "SELECT USERNAME FROM USERS";
                                                             
my $sth = $dbh->prepare($sql)
    or die "Can't prepare statement: $DBI::errstr";
                                                             
$sth->execute();

print $sth;

$dbh->disconnect;
[download]

For testing better use the default current working directory. Anyway the Perl dir from your example is not a good choice. ("f_dir" expects a path to the "database").

A quick example (not a style guide!):

The first script will create 3 files: "users.dir", "users.lck" and "users.pag", in the current dir.

The dbm-create.pl script example:

#!/usr/bin/perl -w
use strict;
use DBI;

my $dbh = DBI->connect('dbi:DBM:')
    or die "Can't connect to $DBI::errstr";

my $sql_create = 'CREATE TABLE users ( username TEXT, phone TEXT )';
$dbh->do($sql_create);

$dbh->do(
    "INSERT INTO users VALUES ('user1', '123-321123')"
);

$dbh->disconnect;
[download]

The dbm-select.pl script example:

#!/usr/bin/perl -w
use strict;
use DBI;

my $dbh = DBI->connect('dbi:DBM:')
    or die "Can't connect to $DBI::errstr";

my $sql = "SELECT username, phone FROM users";

my $sth = $dbh->prepare($sql)
    or die "Can't prepare statement: $DBI::errstr";

$sth->execute();

while ( my $rec = $sth->fetchrow_hashref('NAME_lc') ) {
    print $rec->{username}, ' : ', $rec->{phone}, "\n";
}

$dbh->disconnect;
[download]