to L<DBIx::Class::Schema/connect>. For a list of available limit dialects
see L<DBIx::Class::SQLMaker::LimitDialects>.
-=head2 sth
-
-=over 4
-
-=item Arguments: $sql
-
-=back
-
-Returns a L<DBI> sth (statement handle) for the supplied SQL.
-
=cut
sub _dbh_sth {