Indeed so! However, in your particular case it is not necessarily the context but thorough understanding of the tools used that is lacking ;-).
Same occurred to me just recently when I was playing with the
Class::DBI module. My database contained a dozen tables. A few of these tables served as a cross-reference: they linked data from two tables together. So, when I set out to create a
Class::DBI for a joint table like so:
package YV::Table::ArticleAuthor;
use base 'YV::Table::DBI';
__PACKAGE__->table('article_authors');
__PACKAGE__->columns(All => qw/author_id article_id/);
__PACKAGE__->hasa(YV::Table::Author => 'author_id');
__PACKAGE__->hasa(YV::Table::Article => 'article_id');
# other methods
And later in my code tried to do something like this:
use YV::Table::ArticleAuthor;
# this is built dynamically...
my %delete_article_xref = (
23 => 1,
);
# $author is an YV::Table::Author object initialized prior..
my @author_articles = YV::Table::ArticleAuthor->search(author_id => $a
+uthor->id);
# delete cross reference for $author and article id
# (In affect, I want to 'disassociate' article with $article_id from t
+he $author)
for (@author_articles) {
next unless $delete_article_xref{$_->article_id};
$_[0]->delete();
}
Guess what happened next from here?
Answer (select text):
As a result of invoking the delete() method on an instance of the YV::Table::ArticleAuthor object, I removed all article to author associations. That is, not just one article from a single (selected) author. This caused a little havoc with a web tool I wrote..
The actual problem rested with my lack of understanding how Class::DBI worked. Looking back at the documentation, I figured that the reason the delete() method was acting so 'strangely' was because the primary column of the YV::Table::ArticleAuthor class was in fact author_id and delete() uses this very column to construct (or rather 'restrict') it's DELETE SQL. So the quick fix to my problem was to swap the fields like so:
__PACKAGE__->columns(All => qw/article_id author_id/);
And since the first column is (by default) taken to be the primary column, delete worked as I wanted it to thereafter. ;-).
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Update: err.. I submitted invalid code initially (was taking it from my head heh). This is fixed now.
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# Under Construction
