use DBIx::Class::ResultSourceHandle;
use List::Util ();
use Scalar::Util ();
+
use base qw/DBIx::Class/;
+#use Test::Deep::NoTest (qw/eq_deeply/);
+use Data::Dumper::Concise;
+
__PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
=head1 NAME
=head1 OVERLOADING
If a resultset is used in a numeric context it returns the L</count>.
-However, if it is used in a booleand context it is always true. So if
+However, if it is used in a boolean context it is always true. So if
you want to check if a resultset has any results use C<if $rs != 0>.
C<if $rs> will always be true.
# in ::Relationship::Base::search_related (the row method), and furthermore
# the relationship is of the 'single' type. This means that the condition
# provided by the relationship (already attached to $self) is sufficient,
- # as there can be only one row in the databse that would satisfy the
+ # as there can be only one row in the database that would satisfy the
# relationship
}
else {
# Run the query
my $rs = $self->search ($query, {result_class => $self->result_class, %$attrs});
- if (keys %{$rs->_resolved_attrs->{collapse}}) {
+ if ($rs->_resolved_attrs->{collapse}) {
my $row = $rs->next;
carp "Query returned more than one row" if $rs->next;
return $row;
=head2 search_related_rs
This method works exactly the same as search_related, except that
-it guarantees a restultset, even in list context.
+it guarantees a resultset, even in list context.
=cut
=item B<Note>
-As of 0.08100, this method enforces the assumption that the preceeding
+As of 0.08100, this method enforces the assumption that the preceding
query returns only one row. If more than one row is returned, you will receive
a warning:
my $attrs = $self->_resolved_attrs_copy;
- if (keys %{$attrs->{collapse}}) {
+ if ($attrs->{collapse}) {
$self->throw_exception(
'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
);
$attrs->{where}, $attrs
);
- return (@data ? ($self->_construct_object(@data))[0] : undef);
+ return @data
+ ? ($self->_construct_objects(@data))[0]
+ : undef
+ ;
}
: $self->cursor->next
);
return undef unless (@row);
- my ($row, @more) = $self->_construct_object(@row);
+ my ($row, @more) = $self->_construct_objects(@row);
$self->{stashed_objects} = \@more if @more;
return $row;
}
-sub _construct_object {
+# takes a single DBI-row of data and coinstructs as many objects
+# as the resultset attributes call for.
+# This can be a bit of an action at a distance - it takes as an argument
+# the *current* cursor-row (already taken off the $sth), but if
+# collapsing is requested it will keep advancing the cursor either
+# until the current row-object is assembled (the collapser was able to
+# order the result sensibly) OR until the cursor is exhausted (an
+# unordered collapsing resultset effectively triggers ->all)
+
+# FIXME: why the *FUCK* do we pass around DBI data by copy?! Sadly needs
+# assessment before changing...
+#
+sub _construct_objects {
my ($self, @row) = @_;
- my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
+ my $attrs = $self->_resolved_attrs;
+ my $keep_collapsing = $attrs->{collapse};
+
+ my $res_index;
+=begin
+ do {
+ my $me_pref_col = $attrs->{_row_parser}->($row_ref);
+
+ my $container;
+ if ($keep_collapsing) {
+
+ # FIXME - we should be able to remove these 2 checks after the design validates
+ $self->throw_exception ('Collapsing without a top-level collapse-set... can not happen')
+ unless @{$me_ref_col->[2]};
+ $self->throw_exception ('Top-level collapse-set contains a NULL-value... can not happen')
+ if grep { ! defined $_ } @{$me_pref_col->[2]};
+
+ my $main_ident = join "\x00", @{$me_pref_col->[2]};
+
+ if (! $res_index->{$main_ident}) {
+ # this is where we bail out IFF we are ordered, and the $main_ident changes
+
+ $res_index->{$main_ident} = {
+ all_me_pref => [,
+ index => scalar keys %$res_index,
+ };
+ }
+ }
+
+
+
+ $container = $res_index->{$main_ident}{container};
+ };
+
+ push @$container, [ @{$me_pref_col}[0,1] ];
+
+
+
+ } while (
+ $keep_collapsing
+ &&
+ do { $row_ref = [$self->cursor->next]; $self->{stashed_row} = $row_ref if @$row_ref; scalar @$row_ref }
+ );
+
+ # attempt collapse all rows with same collapse identity
+ if (@to_collapse > 1) {
+ my @collapsed;
+ while (@to_collapse) {
+ $self->_merge_result(\@collapsed, shift @to_collapse);
+ }
+ }
+=cut
+
+ my $mepref_structs = $self->_collapse_result(\@row)
or return ();
- my @new = $self->result_class->inflate_result($self->result_source, @$info);
- @new = $self->{_attrs}{record_filter}->(@new)
- if exists $self->{_attrs}{record_filter};
- return @new;
+
+ my $rsrc = $self->result_source;
+ my $res_class = $self->result_class;
+ my $inflator = $res_class->can ('inflate_result');
+
+ my @objs = map {
+ $res_class->$inflator ($rsrc, @$_)
+ } (@$mepref_structs);
+
+ if (my $f = $attrs->{record_filter}) {
+ @objs = map { $f->($_) } @objs;
+ }
+
+ return @objs;
}
+=begin
+
# two arguments: $as_proto is an arrayref of column names,
# $row_ref is an arrayref of the data. If none of the row data
# is defined we return undef (that's copied from the old
}
return undef unless $has_def;
- my $collapse = keys %{ $self->{_attrs}{collapse} || {} };
+ my $collapse = $self->_resolved_attrs->{collapse};
my $rows = [];
my @row = @$row_ref;
do {
: $rels->{$rel}->[0]
);
- }
+ my $attrs = $self->_resolved_attrs;
+ my ($keep_collapsing, $set_ident) = @{$attrs}{qw/collapse _collapse_ident/};
+
+ # FIXME this is temporary, need to calculate in _resolved_attrs
+ $set_ident ||= { me => [ $self->result_source->_pri_cols ], pref => {} };
+
+ my @cur_row = @$row_ref;
+ my (@to_collapse, $last_ident);
+
+ do {
+ my $row_hr = { map { $as_proto->[$_] => $cur_row[$_] } (0 .. $#$as_proto) };
+
+ # see if we are switching to another object
+ # this can be turned off and things will still work
+ # since _merge_prefetch knows about _collapse_ident
+# my $cur_ident = [ @{$row_hr}{@$set_ident} ];
+ my $cur_ident = [];
+ $last_ident ||= $cur_ident;
+
+# if ($keep_collapsing = Test::Deep::eq_deeply ($cur_ident, $last_ident)) {
+# push @to_collapse, $self->result_source->_parse_row (
+# $row_hr,
+# );
+# }
+ } while (
+ $keep_collapsing
+ &&
+ do { @cur_row = $self->cursor->next; $self->{stashed_row} = \@cur_row if @cur_row; }
+ );
+ die Dumper \@to_collapse;
+
+
+ # attempt collapse all rows with same collapse identity
+ if (@to_collapse > 1) {
+ my @collapsed;
+ while (@to_collapse) {
+ $self->_merge_result(\@collapsed, shift @to_collapse);
}
- else {
- push( @$rows, $row );
- return undef;
- }
+ @to_collapse = @collapsed;
+ }
- return 1;
+ # still didn't fully collapse
+ $self->throw_exception ('Resultset collapse failed (theoretically impossible). Maybe a wrong collapse_ident...?')
+ if (@to_collapse > 1);
+
+ return $to_collapse[0];
}
+# two arguments: $as_proto is an arrayref of 'as' column names,
+# $row_ref is an arrayref of the data. The do-while loop will run
+# once if we do not need to collapse the result and will run as long as
+# _merge_result returns a true value. It will return undef if the
+# current added row does not match the previous row, which in turn
+# means we need to stash the row for the subsequent ->next call
+sub _collapse_result {
+ my ( $self, $as_proto, $row_ref ) = @_;
+
+ my $attrs = $self->_resolved_attrs;
+ my ($keep_collapsing, $set_ident) = @{$attrs}{qw/collapse _collapse_ident/};
+
+ die Dumper [$as_proto, $row_ref, $keep_collapsing, $set_ident ];
+
+
+ my @cur_row = @$row_ref;
+ my (@to_collapse, $last_ident);
+
+ do {
+ my $row_hr = { map { $as_proto->[$_] => $cur_row[$_] } (0 .. $#$as_proto) };
+
+ # see if we are switching to another object
+ # this can be turned off and things will still work
+ # since _merge_prefetch knows about _collapse_ident
+# my $cur_ident = [ @{$row_hr}{@$set_ident} ];
+ my $cur_ident = [];
+ $last_ident ||= $cur_ident;
+
+# if ($keep_collapsing = eq_deeply ($cur_ident, $last_ident)) {
+# push @to_collapse, $self->result_source->_parse_row (
+# $row_hr,
+# );
+# }
+ } while (
+ $keep_collapsing
+ &&
+ do { @cur_row = $self->cursor->next; $self->{stashed_row} = \@cur_row if @cur_row; }
+ );
+
+ # attempt collapse all rows with same collapse identity
+}
+=cut
+
+# Takes an arrayref of me/pref pairs and a new me/pref pair that should
+# be merged on a preexisting matching me (or should be pushed into $merged
+# as a new me/pref pair for further invocations). It should be possible to
+# use this function to collapse complete ->all results, provided _collapse_result() is adjusted
+# to provide everything to this sub not to barf when $merged contains more than one
+# arrayref)
+sub _merge_prefetch {
+ my ($self, $merged, $next_row) = @_;
+
+ unless (@$merged) {
+ push @$merged, $next_row;
+ return;
+ }
+
+}
+
=head2 result_source
=over 4
if ($result_class) {
$self->ensure_class_loaded($result_class);
$self->_result_class($result_class);
+ $self->{attrs}{result_class} = $result_class if ref $self;
}
$self->_result_class;
}
# if we multi-prefetch we group_by primary keys only as this is what we would
# get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
- if ( keys %{$attrs->{collapse}} ) {
- $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->primary_columns) ]
+ if ( $attrs->{collapse} ) {
+ $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
}
- $sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $sub_attrs);
+ $sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $attrs);
# this is so that the query can be simplified e.g.
# * ordering can be thrown away in things like Top limit
$self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
}
- return @{ $self->get_cache } if $self->get_cache;
+ if (my $c = $self->get_cache) {
+ return @$c;
+ }
- my @obj;
+ my @objects;
- if (keys %{$self->_resolved_attrs->{collapse}}) {
+ if ($self->_resolved_attrs->{collapse}) {
# Using $self->cursor->all is really just an optimisation.
# If we're collapsing has_many prefetches it probably makes
# very little difference, and this is cleaner than hacking
- # _construct_object to survive the approach
+ # _construct_objects to survive the approach
$self->cursor->reset;
my @row = $self->cursor->next;
while (@row) {
- push(@obj, $self->_construct_object(@row));
+ push(@objects, $self->_construct_objects(@row));
@row = (exists $self->{stashed_row}
? @{delete $self->{stashed_row}}
: $self->cursor->next);
}
} else {
- @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
+ @objects = map { $self->_construct_objects($_) } $self->cursor->all;
}
- $self->set_cache(\@obj) if $self->{attrs}{cache};
+ $self->set_cache(\@objects) if $self->{attrs}{cache};
- return @obj;
+ return @objects;
}
=head2 reset
my $attrs = $self->_resolved_attrs_copy;
delete $attrs->{$_} for qw/collapse select as/;
- $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
+ $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
if ($needs_group_by_subq) {
# make sure no group_by was supplied, or if there is one - make sure it matches
],
},
{ artistid => 5, name => 'Angsty-Whiny Girl', cds => [
- { title => 'My parents sold me to a record company' ,year => 2005 },
+ { title => 'My parents sold me to a record company', year => 2005 },
{ title => 'Why Am I So Ugly?', year => 2006 },
{ title => 'I Got Surgery and am now Popular', year => 2007 }
],
[qw/artistid name/],
[100, 'A Formally Unknown Singer'],
[101, 'A singer that jumped the shark two albums ago'],
- [102, 'An actually cool singer.'],
+ [102, 'An actually cool singer'],
]);
Please note an important effect on your data when choosing between void and
B<keyed on the relationship name>. If the relationship is of type C<multi>
(L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
The process will correctly identify columns holding foreign keys, and will
-transparrently populate them from the keys of the corresponding relation.
+transparently populate them from the keys of the corresponding relation.
This can be applied recursively, and will work correctly for a structure
with an arbitrary depth and width, as long as the relationships actually
exists and the correct column data has been supplied.
}
}
else {
-
# otherwise we intialise select & as to empty
$attrs->{select} = [];
$attrs->{as} = [];
}
}
- $attrs->{collapse} ||= {};
+ # generate selections based on the prefetch helper
if ( my $prefetch = delete $attrs->{prefetch} ) {
- $prefetch = $self->_merge_attr( {}, $prefetch );
-
- my $prefetch_ordering = [];
+ $attrs->{collapse} = 1;
# this is a separate structure (we don't look in {from} directly)
# as the resolver needs to shift things off the lists to work
}
}
- my @prefetch =
- $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
+ my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
# we need to somehow mark which columns came from prefetch
$attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
+ }
+
+ # run through the resulting joinstructure (starting from our current slot)
+ # and unset collapse if proven unnesessary
+ if ($attrs->{collapse} && ref $attrs->{from} eq 'ARRAY') {
- push( @{$attrs->{order_by}}, @$prefetch_ordering );
- $attrs->{_collapse_order_by} = \@$prefetch_ordering;
+ if (@{$attrs->{from}} > 1) {
+
+ # find where our table-spec starts and consider only things after us
+ my @fromlist = @{$attrs->{from}};
+ while (@fromlist) {
+ my $t = shift @fromlist;
+ $t = $t->[0] if ref $t eq 'ARRAY'; #me vs join from-spec mismatch
+ last if ($t->{-alias} && $t->{-alias} eq $alias);
+ }
+
+ for (@fromlist) {
+ $attrs->{collapse} = ! $_->[0]{-is_single}
+ and last;
+ }
+ }
+ else {
+ # no joins - no collapse
+ $attrs->{collapse} = 0;
+ }
}
+ # the row parser generates differently depending on whether collapsing is requested
+ # the need to look at {select} is temporary
+ $attrs->{_row_parser} = $source->_mk_row_parser (
+ @{$attrs}{qw/as collapse select/}
+ );
+
# 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
will fail miserably.
To get around this limitation, you can supply literal SQL to your
-C<select> attibute that contains the C<AS alias> text, eg:
+C<select> attribute that contains the C<AS alias> text, e.g.
select => [\'myfield AS alias']
C<prefetch> can be used with the following relationship types: C<belongs_to>,
C<has_one> (or if you're using C<add_relationship>, any relationship declared
with an accessor type of 'single' or 'filter'). A more complex example that
-prefetches an artists cds, the tracks on those cds, and the tags associted
+prefetches an artists cds, the tracks on those cds, and the tags associated
with that artist is given below (assuming many-to-many from artists to tags):
my $rs = $schema->resultset('Artist')->search(
=back
-Specifes the maximum number of rows for direct retrieval or the number of
+Specifies the maximum number of rows for direct retrieval or the number of
rows per page if the page attribute or method is used.
=head2 offset
projects / dbsrgits/DBIx-Class.git / blobdiff