use DBIx::Abstract;

my $dbx = DBIx::Abstract->connect(...);

sub do_query {
   $dbx->ensure_connection;
   ## do the query;
}

##</code><code>##

$dbh = DBI->connect(...);

sub do_query {
   my $connect;
   eval { 
      ($connect) = $dbh->selectrow_array('SELECT 1');
   };
   if ($@ || !$connect) {
       $dbh = DBI->connect(...) or die "Can't reconnect: $DBI::err";   
   }

   ## do query.
}