It could be leading or trailing spaces, add TRIM to the sql and try s/\s//g in place of chomp on the @ldap elements. Use Data::Dumper to inspect the values. For example

#!/usr/bin/perl
use strict;
use DBI;
use Data::Dumper;

my $dbh = get_dbh(); #as required

# get mysql records
my $sql = "SELECT TRIM(mid),type FROM table
           WHERE type != 'NA'";
my $sth = $dbh->prepare($sql); 
$sth->execute();

my %table = ();
while (my ($mid,$type) = $sth->fetchrow_array){
  $table{$mid} = $type;
}
#print Dumper \%table;

# check ldap records
my @ldap = (" 4\r\n","  5  ","  6  ",7,8,9,1,2,3);
#print Dumper \@ldap;

my @new_ldap = ();
for my $id (@ldap){
  #chomp $id;
  $id =~ s/\s//g;
  if (exists $table{$id}){
    print "[$id] removed\n";
  } else {
    push @new_ldap,$id;
  }
}
#print Dumper \@new_ldap;

[download]
update : removed limit of 15 on sql
poj

In reply to Re: Strings/Numbers aren't equating properly by poj
in thread Strings/Numbers aren't equating properly by M4ver1k

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.