If you're checking logins against a user table, you could count the number of rows that match your u/p combination

my $sql = q{
   select count(*) 
   from app_users 
   where username = ? and 
         password = ?
};

if (($dbh->selectcol_arrayref($sql, undef, $username, $password)->[0] 
+== 1) {
   # We've logged in
} else {
   # login error
}

[download]

Of course, you probably shouldn't store your passwords in plain text. Assuming you've got some sort of one way encryption going on (using Perl's crypt, or a MD5 or SHA module), you could simply replace the test with

if (($dbh->selectcol_arrayref($sql, undef, $username, my_crypt_call($p
+assword))->[0] == 1)

[download]

By the way, don't interpolate variables in your SQL, or you'll make your login susceptible to a SQL injection attack. Always use placeholders

Update: corrected syntax

In reply to Re: DBI & MySQL Login Test by astroboy
in thread DBI & MySQL Login Test by swordfish

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.