1 package SQL::Abstract::Clauses;
6 use base 'SQL::Abstract';
9 shift->next::method(@_)->register_defaults
12 sub register_defaults {
14 $self->{clauses_of}{select} = [ qw(select from where order_by) ];
15 $self->{expand}{select} = sub { shift->_expand_statement(@_) };
16 $self->{render}{select} = sub { shift->_render_statement(@_) };
17 $self->{expand_clause}{'select.select'} = '_expand_maybe_list_expr';
18 $self->{expand_clause}{'select.from'} = sub {
19 $_[0]->_expand_maybe_list_expr($_[1], -ident)
21 $self->{expand_clause}{'select.where'} = 'expand_expr';
22 $self->{expand_clause}{'select.order_by'} = '_expand_order_by';
26 sub _expand_statement {
27 my ($self, $type, $args) = @_;
28 my $ec = $self->{expand_clause};
31 my $val = $args->{$_};
32 if (defined($val) and my $exp = $ec->{"${type}.$_"}) {
41 sub _render_statement {
42 my ($self, $type, $args) = @_;
44 foreach my $clause (@{$self->{clauses_of}{$type}}) {
45 next unless my $clause_expr = $args->{$clause};
46 my ($sql, @bind) = $self->render_expr($clause_expr);
47 next unless defined($sql) and length($sql);
49 $self->_sqlcase(join ' ', split '_', $clause).' '.$sql,
53 return $self->_join_parts(' ', @parts);