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Re: Looping with DBI

by gav^ (Curate)
on Jun 30, 2002 at 05:09 UTC ( #178316=note: print w/replies, xml ) Need Help??

in reply to Looping with DBI

Here's how I'd do it:
my $sth_news = $dbh->prepare("SELECT id, body FROM news"); $sth_news->execute; $sth_news->bind_columns(\my $news_id, \my $news_body, \my $comments while ($sth_news->fetch) { my $sth_comments = $dbh->prepare("SELECT COUNT(id) FROM comments W +HERE id = ?"); $sth_comments->execute($news_id); $sth_comments->bind_columns(\my $comments); $sth_comments->fetch; print "$news_id, $news_body, $comments"; }
You should look through the DBI docs for information on binding variables, it's bother faster and (in this case) more readable.


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Re: Re: Looping with DBI
by Kanji (Parson) on Jun 30, 2002 at 11:27 UTC

    If you're going to go through the trouble of using bind variables, why not move the second prepare outside the while? That way you avoid needless re-prepareing of the same statement on every iteration of the loop...

    my $sth_news = $dbh->prepare(" SELECT id, body FROM news "); $sth_news->execute; $sth_news->bind_columns(\my $news_id,\my $news_body); my $sth_comments = $dbh->prepare(" SELECT COUNT(id) FROM comments WHERE id = ? "); while ($sth_news->fetch) { $sth_comments->execute($news_id); $sth_comments->bind_columns(\my $comments); $sth_comments->fetch; print "$news_id, $news_body, $comments"; }


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