Hmm, yes, 

my $csv_data = "foo,,bar";
foreach ( split /,/, $csv_data ) {
 print "'$_' => ", defined($_), "\n";
}

[download]

Gives you 

'foo' => 1
'' => 1
'bar' => 1

So that middle value is not undef, but "". Of course, since DBI's results are supposed to be as independent as possible of the underlying data structure, there may -- in fact, should -- be routines within DBD::CSV to convert "" to undef, which is what you'd expect to get if you were using an actual RDBMS. That's assuming it even uses something so crude as that split to get at the data =) 

/me is too lazy to look at the source code.

In reply to Re: Re: Re: Null fields by arturo
in thread Null fields by quietone

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.