use base qw/DBIx::Class/;
use DBIx::Class::Carp;
use DBIx::Class::ResultSetColumn;
-use Scalar::Util qw/blessed weaken/;
+use Scalar::Util qw/blessed weaken reftype/;
use Try::Tiny;
use Data::Compare (); # no imports!!! guard against insane architecture
'bool' => "_bool",
fallback => 1;
+# this is real - CDBICompat overrides it with insanity
+# yes, prototype won't matter, but that's for now ;)
+sub _bool () { 1 }
+
__PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
=head1 NAME
=head3 Resolving conditions and attributes
-When a resultset is chained from another resultset, conditions and
-attributes with the same keys need resolving.
+When a resultset is chained from another resultset (ie:
+C<my $new_rs = $old_rs->search(\%extra_cond, \%attrs)>), conditions
+and attributes with the same keys need resolving.
+
+If any of L</columns>, L</select>, L</as> are present, they reset the
+original selection, and start the selection "clean".
-L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
-into the existing ones from the original resultset.
+The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
+are merged into the existing ones from the original resultset.
The L</where> and L</having> attributes, and any search conditions, are
merged with an SQL C<AND> to the existing condition from the original
my ($source, $attrs) = @_;
$source = $source->resolve
if $source->isa('DBIx::Class::ResultSourceHandle');
+
$attrs = { %{$attrs||{}} };
+ delete @{$attrs}{qw(_sqlmaker_select_args _related_results_construction)};
if ($attrs->{page}) {
$attrs->{rows} ||= 10;
For a list of attributes that can be passed to C<search>, see
L</ATTRIBUTES>. For more examples of using this function, see
L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
-documentation for the first argument, see L<SQL::Abstract>
+documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
and its extension L<DBIx::Class::SQLMaker>.
For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
my $cache;
my %safe = (alias => 1, cache => 1);
if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
- ! defined $_[0]
+ ! defined $call_cond
or
- ref $_[0] eq 'HASH' && ! keys %{$_[0]}
+ ref $call_cond eq 'HASH' && ! keys %$call_cond
or
- ref $_[0] eq 'ARRAY' && ! @{$_[0]}
+ ref $call_cond eq 'ARRAY' && ! @$call_cond
)) {
$cache = $self->get_cache;
}
my $old_attrs = { %{$self->{attrs}} };
- my $old_having = delete $old_attrs->{having};
- my $old_where = delete $old_attrs->{where};
+ my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
my $new_attrs = { %$old_attrs };
# older deprecated name, use only if {columns} is not there
if (my $c = delete $new_attrs->{cols}) {
+ carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
if ($new_attrs->{columns}) {
carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
}
my ($self, $attrs) = @_;
# legacy syntax
- $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
- if exists $attrs->{include_columns};
+ if ( exists $attrs->{include_columns} ) {
+ carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
+ $attrs->{'+columns'} = $self->_merge_attr(
+ $attrs->{'+columns'}, delete $attrs->{include_columns}
+ );
+ }
# columns are always placed first, however
my $self = shift;
return $self->{cursor} ||= do {
- my $attrs = { %{$self->_resolved_attrs } };
+ my $attrs = $self->_resolved_attrs;
$self->result_source->storage->select(
$attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
);
my $attrs = { %{$self->_resolved_attrs} };
$self->throw_exception(
- 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
+ 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
) if $attrs->{collapse};
if ($where) {
$attrs->{from}, $attrs->{select},
$attrs->{where}, $attrs
)];
+
return undef unless @$data;
- $self->{stashed_rows} = [ $data ];
- $self->_construct_objects->[0];
+ $self->{_stashed_rows} = [ $data ];
+ $self->_construct_results->[0];
}
return ($self->all)[0];
}
- return shift(@{$self->{stashed_objects}}) if @{ $self->{stashed_objects}||[] };
+ return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
- $self->{stashed_objects} = $self->_construct_objects
+ $self->{_stashed_results} = $self->_construct_results
or return undef;
- return shift @{$self->{stashed_objects}};
+ return shift @{$self->{_stashed_results}};
}
-# Constructs as many objects as it can in one pass while respecting
+# Constructs as many results as it can in one pass while respecting
# cursor laziness. Several modes of operation:
#
-# * Always builds everything present in @{$self->{stashed_rows}}
+# * Always builds everything present in @{$self->{_stashed_rows}}
# * If called with $fetch_all true - pulls everything off the cursor and
-# builds all objects in one pass
+# builds all result structures (or objects) in one pass
# * If $self->_resolved_attrs->{collapse} is true, checks the order_by
# and if the resultset is ordered properly by the left side:
# * Fetches stuff off the cursor until the "master object" changes,
-# and saves the last extra row (if any) in @{$self->{stashed_rows}}
+# and saves the last extra row (if any) in @{$self->{_stashed_rows}}
# OR
# * Just fetches, and collapses/constructs everything as if $fetch_all
# was requested (there is no other way to collapse except for an
# eager cursor)
# * If no collapse is requested - just get the next row, construct and
# return
-sub _construct_objects {
+sub _construct_results {
my ($self, $fetch_all) = @_;
my $rsrc = $self->result_source;
my $attrs = $self->_resolved_attrs;
- my $cursor = $self->cursor;
+
+ if (
+ ! $fetch_all
+ and
+ ! $attrs->{order_by}
+ and
+ $attrs->{collapse}
+ and
+ my @pcols = $rsrc->primary_columns
+ ) {
+ # default order for collapsing unless the user asked for something
+ $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
+ $attrs->{_ordered_for_collapse} = 1;
+ $attrs->{_order_is_artificial} = 1;
+ }
# this will be used as both initial raw-row collector AND as a RV of
- # _construct_objects. Not regrowing the array twice matters a lot...
- # a suprising amount actually
- my $rows = (delete $self->{stashed_rows}) || [];
+ # _construct_results. Not regrowing the array twice matters a lot...
+ # a surprising amount actually
+ my $rows = delete $self->{_stashed_rows};
+
+ my $cursor; # we may not need one at all
+
+ my $did_fetch_all = $fetch_all;
+
if ($fetch_all) {
# FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
- $rows = [ @$rows, $cursor->all ];
+ $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
}
- elsif (!$attrs->{collapse}) {
+ elsif( $attrs->{collapse} ) {
+
+ # a cursor will need to be closed over in case of collapse
+ $cursor = $self->cursor;
+
+ $attrs->{_ordered_for_collapse} = (
+ (
+ $attrs->{order_by}
+ and
+ $rsrc->schema
+ ->storage
+ ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
+ ) ? 1 : 0
+ ) unless defined $attrs->{_ordered_for_collapse};
+
+ if (! $attrs->{_ordered_for_collapse}) {
+ $did_fetch_all = 1;
+
+ # instead of looping over ->next, use ->all in stealth mode
+ # *without* calling a ->reset afterwards
+ # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
+ if (! $cursor->{_done}) {
+ $rows = [ ($rows ? @$rows : ()), $cursor->all ];
+ $cursor->{_done} = 1;
+ }
+ }
+ }
+
+ if (! $did_fetch_all and ! @{$rows||[]} ) {
# FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
- push @$rows, do { my @r = $cursor->next; @r ? \@r : () }
- unless @$rows;
+ $cursor ||= $self->cursor;
+ if (scalar (my @r = $cursor->next) ) {
+ $rows = [ \@r ];
+ }
}
- else {
- $attrs->{_ordered_for_collapse} ||= (!$attrs->{order_by}) ? undef : do {
- my $st = $rsrc->schema->storage;
- my @ord_cols = map
- { $_->[0] }
- ( $st->_extract_order_criteria($attrs->{order_by}) )
- ;
- my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
+ return undef unless @{$rows||[]};
- for (0 .. $#ord_cols) {
- if (
- ! $colinfos->{$ord_cols[$_]}
- or
- $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
- ) {
- splice @ord_cols, $_;
- last;
- }
+ # sanity check - people are too clever for their own good
+ if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
+
+ my $multiplied_selectors;
+ for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
+ if (
+ $aliastypes->{multiplying}{$sel_alias}
+ or
+ scalar grep { $aliastypes->{multiplying}{(values %$_)[0]} } @{ $aliastypes->{selecting}{$sel_alias}{-parents} }
+ ) {
+ $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
}
+ }
- # since all we check here are the start of the order_by belonging to the
- # top level $rsrc, a present identifying set will mean that the resultset
- # is ordered by its leftmost table in a tsable manner
- (@ord_cols and $rsrc->_identifying_column_set({ map
- { $colinfos->{$_}{-colname} => $colinfos->{$_} }
- @ord_cols
- })) ? 1 : 0;
- };
+ for my $i (0 .. $#{$attrs->{as}} ) {
+ my $sel = $attrs->{select}[$i];
- if ($attrs->{_ordered_for_collapse}) {
- push @$rows, do { my @r = $cursor->next; @r ? \@r : () };
- }
- # instead of looping over ->next, use ->all in stealth mode
- # *without* calling a ->reset afterwards
- # FIXME - encapsulation breach, got to be a better way
- elsif (! $cursor->{_done}) {
- push @$rows, $cursor->all;
- $cursor->{_done} = 1;
- $fetch_all = 1;
+ if (ref $sel eq 'SCALAR') {
+ $sel = $$sel;
+ }
+ elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
+ $sel = $$sel->[0];
+ }
+
+ $self->throw_exception(
+ 'Result collapse not possible - selection from a has_many source redirected to the main object'
+ ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
}
}
- return undef unless @$rows;
+ # hotspot - skip the setter
+ my $res_class = $self->_result_class;
- my $res_class = $self->result_class;
- my $inflator = $res_class->can ('inflate_result')
- or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
+ my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
+ $res_class->can ('inflate_result')
+ or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
+ };
my $infmap = $attrs->{as};
- if (!$attrs->{collapse} and $attrs->{_single_object_inflation}) {
- # construct a much simpler array->hash folder for the one-table cases right here
+ $self->{_result_inflator}{is_core_row} = ( (
+ $inflator_cref
+ ==
+ ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
+ ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
+
+ $self->{_result_inflator}{is_hri} = ( (
+ ! $self->{_result_inflator}{is_core_row}
+ and
+ $inflator_cref == (
+ require DBIx::Class::ResultClass::HashRefInflator
+ &&
+ DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
+ )
+ ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
+
+ if (! $attrs->{_related_results_construction}) {
+ # construct a much simpler array->hash folder for the one-table cases right here
+ if ($self->{_result_inflator}{is_hri}) {
+ for my $r (@$rows) {
+ $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
+ }
+ }
# FIXME SUBOPTIMAL this is a very very very hot spot
# while rather optimal we can *still* do much better, by
- # building a smarter [Row|HRI]::inflate_result(), and
+ # building a smarter Row::inflate_result(), and
# switch to feeding it data via a much leaner interface
#
# crude unscientific benchmarking indicated the shortcut eval is not worth it for
# this particular resultset size
- if (@$rows < 60) {
- my @as_idx = 0..$#$infmap;
+ elsif (@$rows < 60) {
for my $r (@$rows) {
- $r = $inflator->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } @as_idx } );
+ $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
}
}
else {
eval sprintf (
- '$_ = $inflator->($res_class, $rsrc, { %s }) for @$rows',
+ '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
);
}
}
else {
- $self->{_row_parser} ||= eval sprintf 'sub { %s }', $rsrc->_mk_row_parser({
+ my $parser_type =
+ $self->{_result_inflator}{is_hri} ? 'hri'
+ : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
+ : 'classic_nonpruning'
+ ;
+
+ # $args and $attrs to _mk_row_parser are seperated to delineate what is
+ # core collapser stuff and what is dbic $rs specific
+ @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
+ eval => 1,
inflate_map => $infmap,
- selection => $attrs->{select},
collapse => $attrs->{collapse},
premultiplied => $attrs->{_main_source_premultiplied},
- }) or die $@;
+ hri_style => $self->{_result_inflator}{is_hri},
+ prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
+ }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
+
+ # column_info metadata historically hasn't been too reliable.
+ # We need to start fixing this somehow (the collapse resolver
+ # can't work without it). Add an explicit check for the *main*
+ # result, hopefully this will gradually weed out such errors
+ #
+ # FIXME - this is a temporary kludge that reduces perfromance
+ # It is however necessary for the time being
+ my ($unrolled_non_null_cols_to_check, $err);
- # modify $rows in-place, shrinking/extending as necessary
- $self->{_row_parser}->($rows, $fetch_all ? () : (
- # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
- sub { my @r = $cursor->next or return; \@r }, # how the collapser gets more rows
- ($self->{stashed_rows} = []), # where does it stuff excess
- ));
+ if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
+
+ $err =
+ 'Collapse aborted due to invalid ResultSource metadata - the following '
+ . 'selections are declared non-nullable but NULLs were retrieved: '
+ ;
+
+ my @violating_idx;
+ COL: for my $i (@$check_non_null_cols) {
+ ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
+ }
+
+ $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
+ if @violating_idx;
+
+ $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
+ }
- $_ = $inflator->($res_class, $rsrc, @$_) for @$rows;
+ my $next_cref =
+ ($did_fetch_all or ! $attrs->{collapse}) ? undef
+ : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
+sub {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ my @r = $cursor->next or return;
+ if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
+ $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
}
+ \@r
+}
+EOS
+ : sub {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ my @r = $cursor->next or return;
+ \@r
+ }
+ ;
- # CDBI compat stuff
- if ($attrs->{record_filter}) {
- $_ = $attrs->{record_filter}->($_) for @$rows;
+ $self->{_row_parser}{$parser_type}{cref}->(
+ $rows,
+ $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
+ );
+
+ # Special-case multi-object HRI - there is no $inflator_cref pass
+ unless ($self->{_result_inflator}{is_hri}) {
+ $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
+ }
}
+ # The @$rows check seems odd at first - why wouldn't we want to warn
+ # regardless? The issue is things like find() etc, where the user
+ # *knows* only one result will come back. In these cases the ->all
+ # is not a pessimization, but rather something we actually want
+ carp_unique(
+ 'Unable to properly collapse has_many results in iterator mode due '
+ . 'to order criteria - performed an eager cursor slurp underneath. '
+ . 'Consider using ->all() instead'
+ ) if ( ! $fetch_all and @$rows > 1 );
+
return $rows;
}
sub result_class {
my ($self, $result_class) = @_;
if ($result_class) {
- unless (ref $result_class) { # don't fire this for an object
- $self->ensure_class_loaded($result_class);
+
+ # don't fire this for an object
+ $self->ensure_class_loaded($result_class)
+ unless ref($result_class);
+
+ if ($self->get_cache) {
+ carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
}
+ # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
+ elsif ($self->{cursor} && $self->{cursor}{_pos}) {
+ $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
+ }
+
$self->_result_class($result_class);
- # THIS LINE WOULD BE A BUG - this accessor specifically exists to
- # permit the user to set result class on one result set only; it only
- # chains if provided to search()
- #$self->{attrs}{result_class} = $result_class if ref $self;
+
+ delete $self->{_result_inflator};
}
$self->_result_class;
}
# software based limiting can not be ported if this $rs is to be used
# in a subquery itself (i.e. ->as_query)
if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
- return $self->_count_subq_rs;
+ return $self->_count_subq_rs($self->{_attrs});
}
else {
- return $self->_count_rs;
+ return $self->_count_rs($self->{_attrs});
}
}
my ($self, $attrs) = @_;
my $rsrc = $self->result_source;
- $attrs ||= $self->_resolved_attrs;
my $tmp_attrs = { %$attrs };
# take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
# overwrite the selector (supplied by the storage)
- $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
- $tmp_attrs->{as} = 'count';
-
- my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
-
- return $tmp_rs;
+ $rsrc->resultset_class->new($rsrc, {
+ %$tmp_attrs,
+ select => $rsrc->storage->_count_select ($rsrc, $attrs),
+ as => 'count',
+ })->get_column ('count');
}
#
my ($self, $attrs) = @_;
my $rsrc = $self->result_source;
- $attrs ||= $self->_resolved_attrs;
my $sub_attrs = { %$attrs };
# extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
- delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
+ delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
# if we multi-prefetch we group_by something unique, as this is what we would
# get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
->get_column ('count');
}
-sub _bool {
- return 1;
-}
=head2 count_literal
$self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
}
- delete @{$self}{qw/stashed_rows stashed_objects/};
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
if (my $c = $self->get_cache) {
return @$c;
$self->cursor->reset;
- my $objs = $self->_construct_objects('fetch_all') || [];
+ my $objs = $self->_construct_results('fetch_all') || [];
$self->set_cache($objs) if $self->{attrs}{cache};
sub reset {
my ($self) = @_;
- delete @{$self}{qw/stashed_rows stashed_objects/};
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
$self->{all_cache_position} = 0;
$self->cursor->reset;
return $self;
my $attrs = { %{$self->_resolved_attrs} };
my $join_classifications;
- my $existing_group_by = delete $attrs->{group_by};
+ my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
# do we need a subquery for any reason?
my $needs_subq = (
# simplify the joinmap, so we can further decide if a subq is necessary
if (!$needs_subq and @{$attrs->{from}} > 1) {
- $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $self->{cond}, $attrs);
-
- # check if there are any joins left after the prune
- if ( @{$attrs->{from}} > 1 ) {
- $join_classifications = $storage->_resolve_aliastypes_from_select_args (
- [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
- $attrs->{select},
- $self->{cond},
- $attrs
- );
- # any non-pruneable joins imply subq
- $needs_subq = scalar keys %{ $join_classifications->{restricting} || {} };
- }
+ ($attrs->{from}, $join_classifications) =
+ $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $self->{cond}, $attrs);
+
+ # any non-pruneable non-local restricting joins imply subq
+ $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
}
# check if the head is composite (by now all joins are thrown out unless $needs_subq)
);
# make a new $rs selecting only the PKs (that's all we really need for the subq)
- delete $attrs->{$_} for qw/collapse select _prefetch_selector_range as/;
+ delete $attrs->{$_} for qw/select as collapse/;
$attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
- $attrs->{group_by} = \ ''; # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins
+
+ # this will be consumed by the pruner waaaaay down the stack
+ $attrs->{_force_prune_multiplying_joins} = 1;
+
my $subrs = (ref $self)->new($rsrc, $attrs);
if (@$idcols == 1) {
my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
- my %new = (
+ my $new = $self->result_class->new({
%$merged_cond,
- @$cols_from_relations
+ ( @$cols_from_relations
? (-cols_from_relations => $cols_from_relations)
- : (),
+ : ()
+ ),
-result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
- );
+ });
- return $self->result_class->new(\%new);
+ if (
+ reftype($new) eq 'HASH'
+ and
+ ! keys %$new
+ and
+ blessed($new)
+ ) {
+ carp_unique (sprintf (
+ "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
+ $self->result_class,
+ ));
+ }
+
+ $new;
}
# _merge_with_rscond
my $attrs = { %{ $self->_resolved_attrs } };
- # For future use:
- #
- # in list ctx:
- # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
- # $sql also has no wrapping parenthesis in list ctx
- #
- my $sqlbind = $self->result_source->storage
- ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
+ my $aq = $self->result_source->storage->_select_args_to_query (
+ $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
+ );
+
+ $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
- return $sqlbind;
+ $aq;
}
=head2 find_or_new
{ artist => 'fred' }, { key => 'artists' });
$cd->cd_to_producer->find_or_new({ producer => $producer },
- { key => 'primary });
+ { key => 'primary' });
Find an existing record from this resultset using L</find>. if none exists,
instantiate a new result object and return it. The object will not be saved
=cut
sub create {
- my ($self, $attrs) = @_;
+ my ($self, $col_data) = @_;
$self->throw_exception( "create needs a hashref" )
- unless ref $attrs eq 'HASH';
- return $self->new_result($attrs)->insert;
+ unless ref $col_data eq 'HASH';
+ return $self->new_result($col_data)->insert;
}
=head2 find_or_create
sub related_resultset {
my ($self, $rel) = @_;
- $self->{related_resultsets} ||= {};
- return $self->{related_resultsets}{$rel} ||= do {
+ return $self->{related_resultsets}{$rel}
+ if defined $self->{related_resultsets}{$rel};
+
+ return $self->{related_resultsets}{$rel} = do {
my $rsrc = $self->result_source;
my $rel_info = $rsrc->relationship_info($rel);
#XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
delete @{$attrs}{qw(result_class alias)};
- my $new_cache;
-
- if (my $cache = $self->get_cache) {
- if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
- $new_cache = [ map { @{$_->related_resultset($rel)->get_cache||[]} }
- @$cache ];
- }
- }
-
my $rel_source = $rsrc->related_source($rel);
my $new = do {
where => $attrs->{where},
});
};
- $new->set_cache($new_cache) if $new_cache;
+
+ if (my $cache = $self->get_cache) {
+ my @related_cache = map
+ { @{$_->related_resultset($rel)->get_cache||[]} }
+ @$cache
+ ;
+
+ $new->set_cache(\@related_cache) if @related_cache;
+ }
+
$new;
};
}
# ->_resolve_join as otherwise they get lost - captainL
my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
- delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
+ delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
}
else {
+ $attrs->{_grouped_by_distinct} = 1;
# distinct affects only the main selection part, not what prefetch may
# add below.
- $attrs->{group_by} = $source->storage->_group_over_selection (
- $attrs->{from},
- $attrs->{select},
- $attrs->{order_by},
- );
+ $attrs->{group_by} = $source->storage->_group_over_selection($attrs);
}
}
my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
- # we need to somehow mark which columns came from prefetch
- if (@prefetch) {
- my $sel_end = $#{$attrs->{select}};
- $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
- }
-
push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
}
- if ( ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
- $attrs->{_single_object_inflation} = 1;
- $attrs->{collapse} = 0;
+ if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
+ $attrs->{_related_results_construction} = 1;
}
# run through the resulting joinstructure (starting from our current slot)
if (ref $attrs->{from} eq 'ARRAY') {
- if (@{$attrs->{from}} <= 1) {
+ if (@{$attrs->{from}} == 1) {
# no joins - no collapse
$attrs->{collapse} = 0;
}
}
}
- if (! $attrs->{order_by} and $attrs->{collapse}) {
- # default order for collapsing unless the user asked for something
- $attrs->{order_by} = [ map { "$alias.$_" } $source->primary_columns ];
- $attrs->{_ordered_for_collapse} = 1;
- $attrs->{_order_is_artificial} = 1;
- }
-
# if both page and offset are specified, produce a combined offset
# even though it doesn't make much sense, this is what pre 081xx has
# been doing
# A cursor in progress can't be serialized (and would make little sense anyway)
# the parser can be regenerated (and can't be serialized)
- delete @{$to_serialize}{qw/cursor _row_parser/};
+ delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
# nor is it sensical to store a not-yet-fired-count pager
if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
}
}
+1;
+
+__END__
+
# XXX: FIXME: Attributes docs need clearing up
=head1 ATTRIBUTES
=over 4
-=item Value: \@columns
+=item Value: \@columns | \%columns | $column
=back
expression). Adds C<me.> onto the start of any column without a C<.> in
it and sets C<select> from that, then auto-populates C<as> from
C<select> as normal. (You may also use the C<cols> attribute, as in
-earlier versions of DBIC.)
+earlier versions of DBIC, but this is deprecated.)
Essentially C<columns> does the same as L</select> and L</as>.
=back
-Indicates additional columns to be selected from storage. Works the same
-as L</columns> but adds columns to the selection. (You may also use the
-C<include_columns> attribute, as in earlier versions of DBIC). For
-example:-
+Indicates additional columns to be selected from storage. Works the same as
+L</columns> but adds columns to the selection. (You may also use the
+C<include_columns> attribute, as in earlier versions of DBIC, but this is
+deprecated). For example:-
$schema->resultset('CD')->search(undef, {
'+columns' => ['artist.name'],
=back
-=head2 +as
-
-=over 4
-
-Indicates additional column names for those added via L</+select>. See L</as>.
-
-=back
-
=head2 as
=over 4
You can create your own accessors if required - see
L<DBIx::Class::Manual::Cookbook> for details.
+=head2 +as
+
+=over 4
+
+Indicates additional column names for those added via L</+select>. See L</as>.
+
+=back
+
=head2 join
=over 4
will return a set of all artists that have both a cd with title 'Down
to Earth' and a cd with title 'Popular'.
-If you want to fetch related objects from other tables as well, see C<prefetch>
+If you want to fetch related objects from other tables as well, see L</prefetch>
below.
NOTE: An internal join-chain pruner will discard certain joins while
For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
-=head2 prefetch
+=head2 collapse
=over 4
-=item Value: ($rel_name | \@rel_names | \%rel_names)
+=item Value: (0 | 1)
=back
-Contains one or more relationships that should be fetched along with
-the main query (when they are accessed afterwards the data will
-already be available, without extra queries to the database). This is
-useful for when you know you will need the related objects, because it
-saves at least one query:
-
- my $rs = $schema->resultset('Tag')->search(
- undef,
- {
- prefetch => {
- cd => 'artist'
- }
- }
- );
-
-The initial search results in SQL like the following:
-
- SELECT tag.*, cd.*, artist.* FROM tag
- JOIN cd ON tag.cd = cd.cdid
- JOIN artist ON cd.artist = artist.artistid
-
-L<DBIx::Class> has no need to go back to the database when we access the
-C<cd> or C<artist> relationships, which saves us two SQL statements in this
-case.
-
-Simple prefetches will be joined automatically, so there is no need
-for a C<join> attribute in the above search.
-
-L</prefetch> can be used with the any of the relationship types and
-multiple prefetches can be specified together. Below is a more complex
-example that prefetches a CD's artist, its liner notes (if present),
-the cover image, the tracks on that cd, and the guests on those
-tracks.
-
- # Assuming:
- My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
- My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
- My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
- My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
-
- My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
-
- My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
-
-
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- prefetch => [
- { artist => 'record_label'}, # belongs_to => belongs_to
- 'liner_note', # might_have
- 'cover_image', # has_one
- { tracks => 'guests' }, # has_many => has_many
- ]
- }
- );
+When set to a true value, indicates that any rows fetched from joined has_many
+relationships are to be aggregated into the corresponding "parent" object. For
+example, the resultset:
-This will produce SQL like the following:
-
- SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
- tracks.*, guests.*
- FROM cd me
- JOIN artist artist
- ON artist.artistid = me.artistid
- JOIN record_label record_label
- ON record_label.labelid = artist.labelid
- LEFT JOIN track tracks
- ON tracks.cdid = me.cdid
- LEFT JOIN guest guests
- ON guests.trackid = track.trackid
- LEFT JOIN liner_notes liner_note
- ON liner_note.cdid = me.cdid
- JOIN cd_artwork cover_image
- ON cover_image.cdid = me.cdid
- ORDER BY tracks.cd
-
-Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
-C<tracks>, and C<guests> of the CD will all be available through the
-relationship accessors without the need for additional queries to the
-database.
-
-However, there is one caveat to be observed: it can be dangerous to
-prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
-relationship on a given level. e.g.:
-
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- prefetch => [
- 'tracks', # has_many
- { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
- ]
- }
- );
-
-The collapser currently can't identify duplicate tuples for multiple
-L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
-result the second L<has_many|DBIx::Class::Relationship/has_many>
-relation could contain redundant objects.
+ my $rs = $schema->resultset('CD')->search({}, {
+ '+columns' => [ qw/ tracks.title tracks.position / ],
+ join => 'tracks',
+ collapse => 1,
+ });
-=head3 Using L</prefetch> with L</join>
+While executing the following query:
-L</prefetch> implies a L</join> with the equivalent argument, and is
-properly merged with any existing L</join> specification. So the
-following:
+ SELECT me.*, tracks.title, tracks.position
+ FROM cd me
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
- my $rs = $schema->resultset('CD')->search(
- {'record_label.name' => 'Music Product Ltd.'},
- {
- join => {artist => 'record_label'},
- prefetch => 'artist',
- }
- );
+Will return only as many objects as there are rows in the CD source, even
+though the result of the query may span many rows. Each of these CD objects
+will in turn have multiple "Track" objects hidden behind the has_many
+generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
+of this resultset would be as many CD objects as there are tracks (a "Cartesian
+product"), with each CD object containing exactly one of all fetched Track data.
-... will work, searching on the record label's name, but only
-prefetching the C<artist>.
+When a collapse is requested on a non-ordered resultset, an order by some
+unique part of the main source (the left-most table) is inserted automatically.
+This is done so that the resultset is allowed to be "lazy" - calling
+L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
+object with all of its related data.
-=head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
+If an L</order_by> is already declared, and orders the resultset in a way that
+makes collapsing as described above impossible (e.g. C<< ORDER BY
+has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
+switch to "eager" mode and slurp the entire resultset before consturcting the
+first object returned by L</next>.
-L</prefetch> implies a L</+select>/L</+as> with the fields of the
-prefetched relations. So given:
+Setting this attribute on a resultset that does not join any has_many
+relations is a no-op.
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- select => ['cd.title'],
- as => ['cd_title'],
- prefetch => 'artist',
- }
- );
+For a more in-depth discussion, see L</PREFETCHING>.
-The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
-becomes: C<'cd_title', 'artist.*'>.
-
-=head3 CAVEATS
-
-Prefetch does a lot of deep magic. As such, it may not behave exactly
-as you might expect.
+=head2 prefetch
=over 4
-=item *
+=item Value: ($rel_name | \@rel_names | \%rel_names)
-Prefetch uses the L</cache> to populate the prefetched relationships. This
-may or may not be what you want.
+=back
-=item *
+This attribute is a shorthand for specifying a L</join> spec, adding all
+columns from the joined related sources as L</+columns> and setting
+L</collapse> to a true value. For example, the following two queries are
+equivalent:
-If you specify a condition on a prefetched relationship, ONLY those
-rows that match the prefetched condition will be fetched into that relationship.
-This means that adding prefetch to a search() B<may alter> what is returned by
-traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
-
- my $artist_rs = $schema->resultset('Artist')->search({
- 'cds.year' => 2008,
- }, {
- join => 'cds',
+ my $rs = $schema->resultset('Artist')->search({}, {
+ prefetch => { cds => ['genre', 'tracks' ] },
});
- my $count = $artist_rs->first->cds->count;
+and
- my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+ my $rs = $schema->resultset('Artist')->search({}, {
+ join => { cds => ['genre', 'tracks' ] },
+ collapse => 1,
+ '+columns' => [
+ (map
+ { +{ "cds.$_" => "cds.$_" } }
+ $schema->source('Artist')->related_source('cds')->columns
+ ),
+ (map
+ { +{ "cds.genre.$_" => "genre.$_" } }
+ $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
+ ),
+ (map
+ { +{ "cds.tracks.$_" => "tracks.$_" } }
+ $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
+ ),
+ ],
+ });
- my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+Both producing the following SQL:
+
+ SELECT me.artistid, me.name, me.rank, me.charfield,
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
+ genre.genreid, genre.name,
+ tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
+ FROM artist me
+ LEFT JOIN cd cds
+ ON cds.artist = me.artistid
+ LEFT JOIN genre genre
+ ON genre.genreid = cds.genreid
+ LEFT JOIN track tracks
+ ON tracks.cd = cds.cdid
+ ORDER BY me.artistid
+
+While L</prefetch> implies a L</join>, it is ok to mix the two together, as
+the arguments are properly merged and generally do the right thing. For
+example, you may want to do the following:
+
+ my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
+ { 'genre.genreid' => undef },
+ {
+ join => { cds => 'genre' },
+ prefetch => 'cds',
+ }
+ );
- cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
+Which generates the following SQL:
-that cmp_ok() may or may not pass depending on the datasets involved. This
-behavior may or may not survive the 0.09 transition.
+ SELECT me.artistid, me.name, me.rank, me.charfield,
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
+ FROM artist me
+ LEFT JOIN cd cds
+ ON cds.artist = me.artistid
+ LEFT JOIN genre genre
+ ON genre.genreid = cds.genreid
+ WHERE genre.genreid IS NULL
+ ORDER BY me.artistid
-=back
+For a more in-depth discussion, see L</PREFETCHING>.
=head2 alias
... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
query.
+=head1 PREFETCHING
+
+DBIx::Class supports arbitrary related data prefetching from multiple related
+sources. Any combination of relationship types and column sets are supported.
+If L<collapsing|/collapse> is requested, there is an additional requirement of
+selecting enough data to make every individual object uniquely identifiable.
+
+Here are some more involved examples, based on the following relationship map:
+
+ # Assuming:
+ My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
+ My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
+ My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
+
+ My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
+
+ My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
+
+
+
+ my $rs = $schema->resultset('Tag')->search(
+ undef,
+ {
+ prefetch => {
+ cd => 'artist'
+ }
+ }
+ );
+
+The initial search results in SQL like the following:
+
+ SELECT tag.*, cd.*, artist.* FROM tag
+ JOIN cd ON tag.cd = cd.cdid
+ JOIN artist ON cd.artist = artist.artistid
+
+L<DBIx::Class> has no need to go back to the database when we access the
+C<cd> or C<artist> relationships, which saves us two SQL statements in this
+case.
+
+Simple prefetches will be joined automatically, so there is no need
+for a C<join> attribute in the above search.
+
+The L</prefetch> attribute can be used with any of the relationship types
+and multiple prefetches can be specified together. Below is a more complex
+example that prefetches a CD's artist, its liner notes (if present),
+the cover image, the tracks on that CD, and the guests on those
+tracks.
+
+ my $rs = $schema->resultset('CD')->search(
+ undef,
+ {
+ prefetch => [
+ { artist => 'record_label'}, # belongs_to => belongs_to
+ 'liner_note', # might_have
+ 'cover_image', # has_one
+ { tracks => 'guests' }, # has_many => has_many
+ ]
+ }
+ );
+
+This will produce SQL like the following:
+
+ SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
+ tracks.*, guests.*
+ FROM cd me
+ JOIN artist artist
+ ON artist.artistid = me.artistid
+ JOIN record_label record_label
+ ON record_label.labelid = artist.labelid
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
+ LEFT JOIN guest guests
+ ON guests.trackid = track.trackid
+ LEFT JOIN liner_notes liner_note
+ ON liner_note.cdid = me.cdid
+ JOIN cd_artwork cover_image
+ ON cover_image.cdid = me.cdid
+ ORDER BY tracks.cd
+
+Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
+C<tracks>, and C<guests> of the CD will all be available through the
+relationship accessors without the need for additional queries to the
+database.
+
+=head3 CAVEATS
+
+Prefetch does a lot of deep magic. As such, it may not behave exactly
+as you might expect.
+
+=over 4
+
+=item *
+
+Prefetch uses the L</cache> to populate the prefetched relationships. This
+may or may not be what you want.
+
+=item *
+
+If you specify a condition on a prefetched relationship, ONLY those
+rows that match the prefetched condition will be fetched into that relationship.
+This means that adding prefetch to a search() B<may alter> what is returned by
+traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
+
+ my $artist_rs = $schema->resultset('Artist')->search({
+ 'cds.year' => 2008,
+ }, {
+ join => 'cds',
+ });
+
+ my $count = $artist_rs->first->cds->count;
+
+ my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+
+ my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+
+ cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
+
+That cmp_ok() may or may not pass depending on the datasets involved. In other
+words the C<WHERE> condition would apply to the entire dataset, just like
+it would in regular SQL. If you want to add a condition only to the "right side"
+of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
+condition|DBIx::Class::Relationship::Base/condition>
+
+=back
+
=head1 DBIC BIND VALUES
Because DBIC may need more information to bind values than just the column name
[ $name => $val ] === [ { dbic_colname => $name }, $val ]
[ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
[ undef, $val ] === [ {}, $val ]
+ $val === [ {}, $val ]
=head1 AUTHOR AND CONTRIBUTORS
You may distribute this code under the same terms as Perl itself.
-=cut
-
-1;
projects / dbsrgits/DBIx-Class.git / blobdiff