RE: Memoizing non-place-holding sql statements to place-holding


I've read DBI doc but I cann't understand prepare_cached.
Any difference between prepare and prepare_cached?


prepare_cached is useful if you are going to re-use
a statement handle. It stores the statement handle
in a hash keyed by the sql statement itself. This
saves re-preparing the statement if it is reused:

For example:

   my $sth = $dbh->prepare_cached( 'select foo from bar' );

Calls code like:

   my $dbh = shfit;
   my $sql = shift;

   ...

   $cached_statments{ $sql } ||= $dbh->prepare( $sql );

This only does the prepare once (when the ||= finds a
false value in %prepared_statements).

These are useful when you are going to re-run the same
query any number of times from different parts of the
code.



--
Steven Lembark                                       85-09 90th Street
Workhorse Computing                                Woodhaven, NY 11421
lembark@xxxxxxxxxxx                                     1 888 359 3508
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