On Oct 29, 2009, at 5:10 PM, David E. Wheeler wrote:

>  Well, yes. But if there were 'fetch*' and 'select*' keys that could  
>  go to all of them at once, that would be cool, too.

I found another great use for callbacks: A callback on `connected()`  
to set things up for a handle the first time it connects. Bricolage is  
using it for its MySQL support:

http://github.com/bricoleurs/bricolage/commit/68571810c4d79c73e7224471e008398ba9141a8d

The relevant code is:

     Callbacks =>  {
         connected =>  sub {
             my $dbh = shift;
             $dbh-> do(q{
                 SET SESSION  
sql_mode='ansi,strict_trans_tables,no_auto_value_on_zero';
             }) unless exists $dbh-> {private_bric_sql_mode};
             $dbh-> {private_bric_sql_mode} = 1;
             return;
         },
     },

Best,

David