sub _construct_object {
my ($self, @row) = @_;
- my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
+
+ my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
+ or return ();
my @new = $self->result_class->inflate_result($self->result_source, @$info);
@new = $self->{_attrs}{record_filter}->(@new)
if exists $self->{_attrs}{record_filter};
sub _collapse_result {
my ($self, $as_proto, $row) = @_;
+ # if the first row that ever came in is totally empty - this means we got
+ # hit by a smooth^Wempty left-joined resultset. Just noop in that case
+ # instead of producing a {}
+ #
+ my $has_def;
+ for (@$row) {
+ if (defined $_) {
+ $has_def++;
+ last;
+ }
+ }
+ return undef unless $has_def;
+
my @copy = @$row;
# 'foo' => [ undef, 'foo' ]
$tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $tmp_attrs);
$tmp_attrs->{as} = 'count';
- # read the function comment
+ # read the comment on top of the actual function to see what this does
$tmp_attrs->{from} = $self->_switch_to_inner_join_if_needed (
$tmp_attrs->{from}, $tmp_attrs->{alias}
);
my $sub_attrs = { %$attrs };
# extra selectors do not go in the subquery and there is no point of ordering it
- delete $sub_attrs->{$_} for qw/collapse prefetch_select select as order_by/;
+ delete $sub_attrs->{$_} for qw/collapse select _prefetch_select as order_by/;
# if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
# clobber old group_by regardless
$sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $sub_attrs);
- # read the function comment
+ # read the comment on top of the actual function to see what this does
$sub_attrs->{from} = $self->_switch_to_inner_join_if_needed (
$sub_attrs->{from}, $sub_attrs->{alias}
);
+ # this is so that ordering can be thrown away in things like Top limit
+ $sub_attrs->{-for_count_only} = 1;
+
+ my $sub_rs = $rsrc->resultset_class->new ($rsrc, $sub_attrs);
+
$attrs->{from} = [{
- count_subq => $rsrc->resultset_class->new ($rsrc, $sub_attrs )->as_query
+ -alias => 'count_subq',
+ -source_handle => $rsrc->handle,
+ count_subq => $sub_rs->as_query,
}];
# the subquery replaces this
sub _switch_to_inner_join_if_needed {
my ($self, $from, $alias) = @_;
+ # subqueries and other oddness is naturally not supported
return $from if (
ref $from ne 'ARRAY'
||
+ @$from <= 1
+ ||
ref $from->[0] ne 'HASH'
||
! $from->[0]{-alias}
$from->[0]{-alias} eq $alias
);
- # this would be the case with a subquery - we'll never find
- # the target as it is not in the parseable part of {from}
- return $from if @$from == 1;
-
- my (@switch_idx, $found_target);
-
+ my $switch_branch;
JOINSCAN:
- for my $i (1 .. $#$from) {
-
- push @switch_idx, $i;
- my $j = $from->[$i];
- my $jalias = $j->[0]{-alias};
-
- # we found our current target - delete any siblings (same level joins)
- # and bail out
- if ($jalias eq $alias) {
- $found_target++;
-
- my $cur_depth = $j->[0]{-relation_chain_depth};
- # we are -1, so look at -2
- while (@switch_idx > 1
- && $from->[$switch_idx[-2]][0]{-relation_chain_depth} == $cur_depth
- ) {
- splice @switch_idx, -2, 1;
- }
-
+ for my $j (@{$from}[1 .. $#$from]) {
+ if ($j->[0]{-alias} eq $alias) {
+ $switch_branch = $j->[0]{-join_path};
last JOINSCAN;
}
}
# something else went wrong
- return $from unless $found_target;
+ return $from unless $switch_branch;
# So it looks like we will have to switch some stuff around.
# local() is useless here as we will be leaving the scope
# anyway, and deep cloning is just too fucking expensive
# So replace the inner hashref manually
- my @new_from;
- my $sw_idx = { map { $_ => 1 } @switch_idx };
+ my @new_from = ($from->[0]);
+ my $sw_idx = { map { $_ => 1 } @$switch_branch };
- for my $i (0 .. $#$from) {
- if ($sw_idx->{$i}) {
- my %attrs = %{$from->[$i][0]};
- delete $attrs{-join_type};
+ for my $j (@{$from}[1 .. $#$from]) {
+ my $jalias = $j->[0]{-alias};
+ if ($sw_idx->{$jalias}) {
+ my %attrs = %{$j->[0]};
+ delete $attrs{-join_type};
push @new_from, [
\%attrs,
- @{$from->[$i]}[ 1 .. $#{$from->[$i]} ],
+ @{$j}[ 1 .. $#$j ],
];
}
else {
- push @new_from, $from->[$i];
+ push @new_from, $j;
}
}
}
$self->set_cache(\@obj) if $self->{attrs}{cache};
+
return @obj;
}
#
# used to determine if a subquery is neccessary
#
-# supports some virtual attributes:
+# supports some virtual attributes:
# -join
# This will scan for any joins being present on the resultset.
# It is not a mere key-search but a deep inspection of {from}
can also be passed an object representing the foreign row, and the
value will be set to its primary key.
-To create related objects, pass a hashref for the value if the related
-item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
-and use the name of the relationship as the key. (NOT the name of the field,
-necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
-of hashrefs containing the data for each of the rows to create in the foreign
-tables, again using the relationship name as the key.
+To create related objects, pass a hashref of related-object column values
+B<keyed on the relationship name>. If the relationship is of type C<multi>
+(L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
+The process will correctly identify columns holding foreign keys, and will
+transparrently populate them from the keys of the corresponding relation.
+This can be applied recursively, and will work correctly for a structure
+with an arbitrary depth and width, as long as the relationships actually
+exists and the correct column data has been supplied.
+
Instead of hashrefs of plain related data (key/value pairs), you may
also pass new or inserted objects. New objects (not inserted yet, see
# in order to properly resolve prefetch aliases (any alias
# with a relation_chain_depth less than the depth of the
# current prefetch is not considered)
+#
+# The increments happen in 1/2s to make it easier to correlate the
+# join depth with the join path. An integer means a relationship
+# specified via a search_related, whereas a fraction means an added
+# join/prefetch via attributes
sub _chain_relationship {
my ($self, $rel) = @_;
my $source = $self->result_source;
}];
my $seen = { %{$attrs->{seen_join} || {} } };
+ my $jpath = ($attrs->{seen_join} && keys %{$attrs->{seen_join}})
+ ? $from->[-1][0]{-join_path}
+ : [];
+
# we need to take the prefetch the attrs into account before we
# ->_resolve_join as otherwise they get lost - captainL
my $merged = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
- my @requested_joins = $source->_resolve_join($merged, $attrs->{alias}, $seen);
+ my @requested_joins = $source->_resolve_join(
+ $merged,
+ $attrs->{alias},
+ $seen,
+ $jpath,
+ );
push @$from, @requested_joins;
- ++$seen->{-relation_chain_depth};
+ $seen->{-relation_chain_depth} += 0.5;
# if $self already had a join/prefetch specified on it, the requested
# $rel might very well be already included. What we do in this case
# the join in question so we could tell it *is* the search_related)
my $already_joined;
+
# we consider the last one thus reverse
for my $j (reverse @requested_joins) {
if ($rel eq $j->[0]{-join_path}[-1]) {
- $j->[0]{-relation_chain_depth}++;
+ $j->[0]{-relation_chain_depth} += 0.5;
$already_joined++;
last;
}
}
+
+# alternative way to scan the entire chain - not backwards compatible
+# for my $j (reverse @$from) {
+# next unless ref $j eq 'ARRAY';
+# if ($j->[0]{-join_path} && $j->[0]{-join_path}[-1] eq $rel) {
+# $j->[0]{-relation_chain_depth} += 0.5;
+# $already_joined++;
+# last;
+# }
+# }
+
unless ($already_joined) {
- push @$from, $source->_resolve_join($rel, $attrs->{alias}, $seen);
+ push @$from, $source->_resolve_join(
+ $rel,
+ $attrs->{alias},
+ $seen,
+ $jpath,
+ );
}
- ++$seen->{-relation_chain_depth};
+ $seen->{-relation_chain_depth} += 0.5;
return ($from,$seen);
}
# build columns (as long as select isn't set) into a set of as/select hashes
unless ( $attrs->{select} ) {
- @colbits = map {
- ( ref($_) eq 'HASH' )
- ? $_
- : {
- (
- /^\Q${alias}.\E(.+)$/
- ? "$1"
- : "$_"
- )
- =>
- (
- /\./
- ? "$_"
- : "${alias}.$_"
- )
- }
- } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns );
+
+ my @cols = ( ref($attrs->{columns}) eq 'ARRAY' )
+ ? @{ delete $attrs->{columns}}
+ : (
+ ( delete $attrs->{columns} )
+ ||
+ $source->storage->_order_select_columns(
+ $source,
+ [ $source->columns ],
+ )
+ )
+ ;
+
+ @colbits = map {
+ ( ref($_) eq 'HASH' )
+ ? $_
+ : {
+ (
+ /^\Q${alias}.\E(.+)$/
+ ? "$1"
+ : "$_"
+ )
+ =>
+ (
+ /\./
+ ? "$_"
+ : "${alias}.$_"
+ )
+ }
+ } @cols;
}
+
# add the additional columns on
foreach ( 'include_columns', '+columns' ) {
push @colbits, map {
[
@{ $attrs->{from} },
$source->_resolve_join(
- $join, $alias, { %{ $attrs->{seen_join} || {} } }
+ $join,
+ $alias,
+ { %{ $attrs->{seen_join} || {} } },
+ ($attrs->{seen_join} && keys %{$attrs->{seen_join}})
+ ? $attrs->{from}[-1][0]{-join_path}
+ : []
+ ,
)
];
}
- if ( $attrs->{order_by} ) {
+ if ( defined $attrs->{order_by} ) {
$attrs->{order_by} = (
ref( $attrs->{order_by} ) eq 'ARRAY'
? [ @{ $attrs->{order_by} } ]
- : [ $attrs->{order_by} ]
+ : [ $attrs->{order_by} || () ]
);
}
$attrs->{group_by} = [ $attrs->{group_by} ];
}
- # If the order_by is otherwise empty - we will use this for TOP limit
- # emulation and the like.
- # Although this is needed only if the order_by is not defined, it is
- # actually cheaper to just populate this rather than properly examining
- # order_by (stuf like [ {} ] and the like)
- $attrs->{_virtual_order_by} = [ $self->result_source->primary_columns ];
-
+ # generate the distinct induced group_by early, as prefetch will be carried via a
+ # subquery (since a group_by is present)
+ if (delete $attrs->{distinct}) {
+ $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
+ }
$attrs->{collapse} ||= {};
if ( my $prefetch = delete $attrs->{prefetch} ) {
my @prefetch =
$source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
- $attrs->{prefetch_select} = [ map { $_->[0] } @prefetch ];
- push @{ $attrs->{select} }, @{$attrs->{prefetch_select}};
+ # 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);
- push( @{ $attrs->{order_by} }, @$prefetch_ordering );
+ push( @{$attrs->{order_by}}, @$prefetch_ordering );
$attrs->{_collapse_order_by} = \@$prefetch_ordering;
}
-
- if (delete $attrs->{distinct}) {
- $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{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
if (my $page = delete $attrs->{page}) {
- $attrs->{offset} = ($attrs->{rows} * ($page - 1)) +
- ($attrs->{offset} || 0);
+ $attrs->{offset} =
+ ($attrs->{rows} * ($page - 1))
+ +
+ ($attrs->{offset} || 0)
+ ;
}
return $self->{_attrs} = $attrs;
my $paths = {};
return $paths unless ref $fromspec eq 'ARRAY';
+ my $cur_depth = $seen->{-relation_chain_depth} || 0;
+
+ if (int ($cur_depth) != $cur_depth) {
+ $self->throw_exception ("-relation_chain_depth is not an integer, something went horribly wrong ($cur_depth)");
+ }
+
for my $j (@$fromspec) {
next if ref $j ne 'ARRAY';
- next if $j->[0]{-relation_chain_depth} < ( $seen->{-relation_chain_depth} || 0);
+ next if ($j->[0]{-relation_chain_depth} || 0) < $cur_depth;
+
+ my $jpath = $j->[0]{-join_path};
my $p = $paths;
- $p = $p->{$_} ||= {} for @{$j->[0]{-join_path}};
+ $p = $p->{$_} ||= {} for @{$jpath}[$cur_depth .. $#$jpath];
push @{$p->{-join_aliases} }, $j->[0]{-alias};
}
=back
-Which column(s) to order the results by. If a single column name, or
-an arrayref of names is supplied, the argument is passed through
-directly to SQL. The hashref syntax allows for connection-agnostic
-specification of ordering direction:
+Which column(s) to order the results by.
+
+[The full list of suitable values is documented in
+L<SQL::Abstract/"ORDER BY CLAUSES">; the following is a summary of
+common options.]
+
+If a single column name, or an arrayref of names is supplied, the
+argument is passed through directly to SQL. The hashref syntax allows
+for connection-agnostic specification of ordering direction:
For descending order:
B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
attributes will be ignored.
+B<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. This
+behavior may or may not survive the 0.09 transition.
+
+=back
+
=head2 page
=over 4
projects / dbsrgits/DBIx-Class.git / blobdiff