Since DBI's prepare_cached statement handle method caches the prepared statement handle in the database handle object, you could also do:
my $if_active = 1;
my $address_exists_sth = $dbh->prepare_cached(
   'SELECT * FROM EMAILS WHERE `email`=?', 
   { sub =>'address_exists' },
   $if_active,
);

[download]
in address_exists as long as you call $address_exists_sth->finish before exiting address_exists or set $if_active to whatever is appropriate, i.e. probably 1 (automatically call $sth->finish), though 3 (create a new statement handle and remove the previous one from the cache) is an option if you are using DBI greater than 1.40.

If this code is not guaranteed to be tied forever to MySQL, I would also replace the use of `s for quoting column names (which is a MySQLism) with "s which is more portable, including to MySQL.

In reply to Re^2: prepared statement by james2vegas
in thread prepared statement by saintex

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