Please could somebody enlighten me on the ins and outs of the following error message. 

Use of uninitialized value in join or string at C:/Perl_activate/20_Oc
+tober_2005_L.pl line 438, <FLAT_FILE> line 1191.

[download]
in relation to the following code. 

    my $sth_C = $dbh->prepare($Return_results) or die "Couldn't prepar
+e query: ".$dbh->errstr;
    
    $sth_C->execute() or die "Couldn't execute query: ".$sth_C->errstr
+;
    
        while (my @row = $sth_C->fetchrow_array) {
             
      print OUTPUT_FILE join("\t", @row);  ###<< The error message app
+lies to this line of code.
      print OUTPUT_FILE "\n";
      
      undef @row;

[download]

In reply to uninitialized value in join or string by Win

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.