1. What value is stored in @intervals

Since @intervals denotes an array, most likely it holds a list of values - only one would just be a special case. The array holds what is returned from the search method of the object provided by resultset.

If in doubt, have a look:

{
    my $c;
    for my $thingy (@intervals) {
        printf "%2d. '%s'\n",++$c, $thingy;
    }
}

[download]
2. How is it possible to have 'Aggregation' in code and 'aggregation' table in database

It's possible with some piece of software which does the connection between 'Aggregation' and 'aggregation', probably by upper-/lowercasing the identifier.

3. What does 'undef' signify here.

It means just what undef means anywhere else: a placeholder for nothing, which is just about the same as the NULL value in a database cell.

Have a look at the documentation of DBIx::Class and DBIx::Class::ResultSet.

In reply to Re: Database MySQL Perl by shmem
in thread Database MySQL Perl by akagrawal3

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.