Update:I cleaned up a redundant subroutine call in my code.

You need to get the information out with a custom sql statement and put it in some kind of data structure if it exists. There are a lot of ways to do this. a quick example. 

#!/usr/bin/perl -w

use strict;
use DBI;
#db connect
my $driver = 'mysql';
my $database = 'usersdb';
my $dsn = "DBI:$driver:database=$database";
my $dbh = DBI->connect($dsn, undef, undef);
my $user ="bob";
my $user_test = user_exists($user);
if (defined $user_test){
    print "user $user is already in our database";
}else{
    #code to insert user
}

$dbh->disconnect;

sub user_exists{
    my $id_val = shift;
    my $statement = "select user_id from users where user_id = $id_val
+";
    my $ary_ref = $dbh->selectall_arrayref($statement);
    if (defined $ary_ref->[0]->[0]){
        return $ary_ref->[0]->[0];
    }else{
        return undef;
    }
    
}

[download]

In reply to Re: mySQL with Perl by thunders
in thread mySQL with Perl by skirrow

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.