Or more succintly, "favor object composition over class inheritance."

And yes, i agree that this is good place to honor that rule, but i would code it the other way around, that is, instead of a DBI having a Calendar, the Calendar should have the DBI: 

package MyCalendar;

use MyDBI;

sub new {
    ...

    $self->{'_dbh'} = MyDBI->connect( ... );

    ...
}

[download]
And connect() should only create a new database connection if an existing database connection does not already exist (that is, MyDBI is a Singleton or behaves like one). Or, as dragonchild suggests, you could simply pass the database connection to the object in question when you instantiate it. But either way, the Object hasa database connection, and the client can (theoretically) not have to learn SQL. ;)

Disclaimer: In reality, i think plain ole DBI's selectall_arrayref() with the {Slice => {}} attribute function parameter offers plenty of power, flexibility, and maintainability, and it takes less time to develop with. But as always, Your Mileage May Vary and There Is Always More Than One Way To Do It.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

In reply to Re^4: OO, inheriting functions from other packages by jeffa
in thread OO, inheriting functions from other packages by sschneid

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.