Personally, I tend to do two things differently:

• First, I select a full list of primary keys and put it in a hash. Before I try to do an insert, I check to see if the primary key for that record exists in the hash. If it does, I do an update instead of an insert. If the primary key isn't in the hash, then I do an insert, and add it to the hash if the insert was successful. This seems to be a little cleaner and (potentially) halves my number of SQL executions.
• Second, I tend to use the RaiseError option in my database connection so that my program doesn't die when DBI encounters an error. I examine $DBI::errstr to specifically identify the nature of the error (in Oracle, you get error codes) so that I cover my bases for the unexpected. There's no sense in attempting an update if the table doesn't exist or your SQL is malformed. I'm not a MySQL guy, but the use of eval and $@ seems less than precise -- you might react to what you think is a duplicate insert error but is really something much more severe.

Update: As noted by kyle above, however, if this code is executed by multiple users/processes, you could end up with a race condition, such that your inserts might still fail because some other guy just added that record since the time that you selected all the primary keys.

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.