Re: using callbacks with connect_cached

Le vendredi 23 août 2013 à 16:25 +0200, David E. Wheeler a écrit :

> Oh, you know what? I think this is why the example in the docs and my blog post puts the callback into a lexical variable, then just passes that lexical. This is because the params passed to connect_cached(), if they vary at all, create different connections. You call connect_cached() three times, and construct the Callbacks hash reference anew each time. So it is different each time.
> 
> Try this:
> 
> my $cb = {
>     'connect_cached.reused' => sub { print "reused!!!"; return; },
> };
> for my $test (1..3) {
>     my $cached_dbh = MyApp::SQLite->connect_cached(
>         "dbi:SQLite:dbname=$dbfile", '', '',
>         {
>             RaiseError  => 1,
>             PrintError  => 0,
>             Callbacks => $cb,
>         }
>     );
>     ...
> }
> 

That did the trick! Congratulations for finding it.

I still can't use connect_cached.new for my original purpose, which was
to send an SQL query setting the correct datestyle for a new connection;
the error returned is :

 Can't call method "do" on an undefined value
at /home/lib/Aspro/db_handle.pm

which seems logical, since DBI.pm's documentation says :

"connect_cached.*" callbacks are invoked before connect_cached() has
applied the connect attributes 

But I found a middle ground (setting the datestyle once at login time,
it is then kept by the cached connection)

Thank you for your help.

-- 
Salutations, Vincent Veyron 
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