use DBI;
use Data::Dump 'pp';
my $dbh = DBI->connect($dbdsn, $dbuserid, $dbpassword, 
 {RaiseError => 1,PrintError => 1})           
 or die "Connection Error: $DBI::errstr\n";

# users 
my $sql_u = 'SELECT id from users';
my $dbUsers = $dbh->selectall_hashref($sql_u,'id');
print "Users\n";
pp $dbUsers;

# regions 
my $sql_r = 'SELECT id,name FROM regions';
my $regions = $dbh->selectall_hashref($sql_r,'name');
print "Regions\n";
pp $regions;

# prepare insert sql
my $sql_i = "INSERT INTO users (id, name, displayname, regionid) 
             VALUES (?,?,?,?)";
my $sth_i = $dbh->prepare($sql_i);
for my $uid (keys %$ldapUsers) {
  # check if user not exists in db
  if (! exists $dbUsers->{$uid}){
    my $ldap = $ldapUsers->{$uid};
    my @f = ($uid);
    $f[1] = $ldap->{'name'};
    $f[2] = $ldap->{'displayName'};
    $f[3] = $regions->{$ldap->{'defaulteRegion'}}{'id'};
    # uncomment the execute after testing
    #$sth_i->execute(@f); 
    print "Insert record : ".(join " | ",@f,"\n");
  }
}