Revision history for DBIx::Class
+ - Fixed regression when both page and offset are specified on
+ a resultset
+ - Fixed HRI returning too many empty results on multilevel
+ nonexisting prefetch
+ - Fixed the prefetch with limit bug
+
0.08107 2009-06-14 08:21:00 (UTC)
- Fix serialization regression introduced in 0.08103 (affects
Cursor::Cached)
So, joins are a way of extending simple select statements to include
fields from other, related, tables. There are various types of joins,
depending on which combination of the data you wish to retrieve, see
-L<MySQL's doc on JOINs|http://dev.mysql.com/doc/refman/5.0/en/join.html>.
+MySQL's doc on JOINs: L<http://dev.mysql.com/doc/refman/5.0/en/join.html>.
=head1 DEFINING JOINS AND RELATIONSHIPS
# if there is at least one defined column consider the resultset real
# (and not an emtpy has_many rel containing one empty hashref)
+ # an empty arrayref is an empty multi-sub-prefetch - don't consider
+ # those either
for (values %$hash) {
- return $hash if defined $_;
+ if (ref $_ eq 'ARRAY') {
+ return $hash if @$_;
+ }
+ elsif (defined $_) {
+ return $hash;
+ }
}
return undef;
Query returned more than one row
-In this case, you should be using L</first> or L</find> instead, or if you really
+In this case, you should be using L</next> or L</find> instead, or if you really
know what you are doing, use the L</rows> attribute to explicitly limit the size
of the resultset.
+This method will also throw an exception if it is called on a resultset prefetching
+has_many, as such a prefetch implies fetching multiple rows from the database in
+order to assemble the resulting object.
+
=back
=cut
my $attrs = $self->_resolved_attrs_copy;
+ if (keys %{$attrs->{collapse}}) {
+ $self->throw_exception(
+ 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
+ );
+ }
+
if ($where) {
if (defined $attrs->{where}) {
$attrs->{where} = {
return $self->search(@_)->count if @_ and defined $_[0];
return scalar @{ $self->get_cache } if $self->get_cache;
- my $meth = $self->_has_attr (qw/prefetch collapse distinct group_by/)
+ my $meth = $self->_has_resolved_attr (qw/collapse group_by/)
? 'count_grouped'
: 'count'
;
my $rsrc = $self->result_source;
- my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
- my $needs_subq = $self->_has_attr (qw/row offset page/);
+ my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
+ my $needs_subq = $self->_has_resolved_attr (qw/row offset/);
if ($needs_group_by_subq or $needs_subq) {
# make a new $rs selecting only the PKs (that's all we really need)
my $attrs = $self->_resolved_attrs_copy;
- delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
+ delete $attrs->{$_} for qw/collapse select as/;
$attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
if ($needs_group_by_subq) {
return 0;
}
-# _has_attr
+# _has_resolved_attr
#
# determines if the resultset defines at least one
# of the attributes supplied
#
# used to determine if a subquery is neccessary
-sub _has_attr {
+sub _has_resolved_attr {
my ($self, @attr_names) = @_;
my $attrs = $self->_resolved_attrs;
my $join_check_req;
for my $n (@attr_names) {
- ++$join_check_req if $n =~ /join/;
+ ++$join_check_req if $n eq '-join';
my $attr = $attrs->{$n};
}
}
- # a join can be expressed as a multi-level from
+ # a resolved join is expressed as a multi-level from
return 1 if (
$join_check_req
and
map { $prefix . $_ } ($source->primary_columns)
];
- my $collapse = $attrs->{collapse} || {};
+ $attrs->{collapse} ||= {};
if ( my $prefetch = delete $attrs->{prefetch} ) {
$prefetch = $self->_merge_attr( {}, $prefetch );
- my @pre_order;
- foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) {
-
- # bring joins back to level of current class
- my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
- my @prefetch =
- $source->_resolve_prefetch( $p, $alias, $join_map, \@pre_order, $collapse );
- push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
- push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
- }
- push( @{ $attrs->{order_by} }, @pre_order );
+
+ my $prefetch_ordering = [];
+
+ my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
+
+ my @prefetch =
+ $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
+
+ push( @{ $attrs->{select} }, map { $_->[0] } @prefetch );
+ push( @{ $attrs->{as} }, map { $_->[1] } @prefetch );
+
+ 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}} ];
}
- $attrs->{collapse} = $collapse;
-
- if ( $attrs->{page} and not defined $attrs->{offset} ) {
- $attrs->{offset} = ( $attrs->{rows} * ( $attrs->{page} - 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
+ if (my $page = delete $attrs->{page}) {
+ $attrs->{offset} = ($attrs->{rows} * ($page - 1)) +
+ ($attrs->{offset} || 0);
}
return $self->{_attrs} = $attrs;
=back
-Alternative method to L</load_namespaces> which you should look at
-using if you can.
+L</load_classes> is an alternative method to L</load_namespaces>, both of
+which serve similar purposes, each with different advantages and disadvantages.
+In the general case you should use L</load_namespaces>, unless you need to
+be able to specify that only specific classes are loaded at runtime.
With no arguments, this method uses L<Module::Find> to find all classes under
the schema's namespace. Otherwise, this method loads the classes you specify
Issues a commit of the current transaction.
+It does I<not> perform an actual storage commit unless there's a DBIx::Class
+transaction currently in effect (i.e. you called L</txn_begin>).
+
=cut
sub txn_commit { die "Virtual method!" }
}
sub _select_args {
- my ($self, $ident, $select, $condition, $attrs) = @_;
+ my ($self, $ident, $select, $where, $attrs) = @_;
my $sql_maker = $self->sql_maker;
$sql_maker->{_dbic_rs_attrs} = $attrs;
- my $order = { map
- { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
- (qw/order_by group_by having _virtual_order_by/ )
- };
-
-
- my $bind_attrs = {};
-
my $alias2source = $self->_resolve_ident_sources ($ident);
+ # calculate bind_attrs before possible $ident mangling
+ my $bind_attrs = {};
for my $alias (keys %$alias2source) {
my $bindtypes = $self->source_bind_attributes ($alias2source->{$alias}) || {};
for my $col (keys %$bindtypes) {
}
}
- # This would be the point to deflate anything found in $condition
- # (and leave $attrs->{bind} intact). Problem is - inflators historically
- # expect a row object. And all we have is a resultsource (it is trivial
- # to extract deflator coderefs via $alias2source above).
- #
- # I don't see a way forward other than changing the way deflators are
- # invoked, and that's just bad...
-
- my @args = ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $condition, $order);
+ my @limit;
if ($attrs->{software_limit} ||
$sql_maker->_default_limit_syntax eq "GenericSubQ") {
$attrs->{software_limit} = 1;
# MySQL actually recommends this approach. I cringe.
$attrs->{rows} = 2**48 if not defined $attrs->{rows} and defined $attrs->{offset};
- push @args, $attrs->{rows}, $attrs->{offset};
+
+ if ($attrs->{rows} && keys %{$attrs->{collapse}}) {
+ ($ident, $select, $where, $attrs)
+ = $self->_adjust_select_args_for_limited_prefetch ($ident, $select, $where, $attrs);
+ }
+ else {
+ push @limit, $attrs->{rows}, $attrs->{offset};
+ }
}
- return @args;
+
+###
+ # This would be the point to deflate anything found in $where
+ # (and leave $attrs->{bind} intact). Problem is - inflators historically
+ # expect a row object. And all we have is a resultsource (it is trivial
+ # to extract deflator coderefs via $alias2source above).
+ #
+ # I don't see a way forward other than changing the way deflators are
+ # invoked, and that's just bad...
+###
+
+ my $order = { map
+ { $attrs->{$_} ? ( $_ => $attrs->{$_} ) : () }
+ (qw/order_by group_by having _virtual_order_by/ )
+ };
+
+
+ $sql_maker->{for} = delete $attrs->{for};
+
+ return ('select', $attrs->{bind}, $ident, $bind_attrs, $select, $where, $order, @limit);
+}
+
+sub _adjust_select_args_for_limited_prefetch {
+ my ($self, $from, $select, $where, $attrs) = @_;
+
+ if ($attrs->{group_by} and @{$attrs->{group_by}}) {
+ $self->throw_exception ('Prefetch with limit (rows/offset) is not supported on resultsets with a group_by attribute');
+ }
+
+ $self->throw_exception ('Prefetch with limit (rows/offset) is not supported on resultsets with a custom from attribute')
+ if (ref $from ne 'ARRAY');
+
+ # separate attributes
+ my $sub_attrs = { %$attrs };
+ delete $attrs->{$_} for qw/where bind rows offset/;
+ delete $sub_attrs->{$_} for qw/for collapse select order_by/;
+
+ my $alias = $attrs->{alias};
+
+ # create subquery select list
+ my $sub_select = [ grep { $_ =~ /^$alias\./ } @{$attrs->{select}} ];
+
+ # bring over all non-collapse-induced order_by into the inner query (if any)
+ # the outer one will have to keep them all
+ if (my $ord_cnt = @{$attrs->{order_by}} - @{$attrs->{_collapse_order_by}} ) {
+ $sub_attrs->{order_by} = [
+ @{$attrs->{order_by}}[ 0 .. ($#{$attrs->{order_by}} - $ord_cnt - 1) ]
+ ];
+ }
+
+
+ # mangle the head of the {from}
+ my $self_ident = shift @$from;
+
+ my %join_info = map { $_->[0]{-alias} => $_->[0] } (@$from);
+
+ my (%inner_joins);
+
+ # decide which parts of the join will remain on the inside
+ #
+ # this is not a very viable optimisation, but it was written
+ # before I realised this, so might as well remain. We can throw
+ # away _any_ branches of the join tree that are:
+ # 1) not mentioned in the condition/order
+ # 2) left-join leaves (or left-join leaf chains)
+ # Most of the join ocnditions will not satisfy this, but for real
+ # complex queries some might, and we might make some RDBMS happy.
+ #
+ #
+ # since we do not have introspectable SQLA, we fall back to ugly
+ # scanning of raw SQL for WHERE, and for pieces of ORDER BY
+ # in order to determine what goes into %inner_joins
+ # It may not be very efficient, but it's a reasonable stop-gap
+ {
+ # produce stuff unquoted, so it can be scanned
+ my $sql_maker = $self->sql_maker;
+ local $sql_maker->{quote_char};
+
+ my @order_by = (map
+ { ref $_ ? $_->[0] : $_ }
+ $sql_maker->_order_by_chunks ($sub_attrs->{order_by})
+ );
+
+ my $where_sql = $sql_maker->where ($where);
+
+ # sort needed joins
+ for my $alias (keys %join_info) {
+
+ # any table alias found on a column name in where or order_by
+ # gets included in %inner_joins
+ # Also any parent joins that are needed to reach this particular alias
+ for my $piece ($where_sql, @order_by ) {
+ if ($piece =~ /\b$alias\./) {
+ $inner_joins{$alias} = 1;
+ }
+ }
+ }
+ }
+
+ # scan for non-leaf/non-left joins and mark as needed
+ # also mark all ancestor joins that are needed to reach this particular alias
+ # (e.g. join => { cds => 'tracks' } - tracks will bring cds too )
+ #
+ # traverse by the size of the -join_path i.e. reverse depth first
+ for my $alias (sort { @{$join_info{$b}{-join_path}} <=> @{$join_info{$a}{-join_path}} } (keys %join_info) ) {
+
+ my $j = $join_info{$alias};
+ $inner_joins{$alias} = 1 if (! $j->{-join_type} || ($j->{-join_type} !~ /^left$/i) );
+
+ if ($inner_joins{$alias}) {
+ $inner_joins{$_} = 1 for (@{$j->{-join_path}});
+ }
+ }
+
+ # construct the inner $from for the subquery
+ my $inner_from = [ $self_ident ];
+ if (keys %inner_joins) {
+ for my $j (@$from) {
+ push @$inner_from, $j if $inner_joins{$j->[0]{-alias}};
+ }
+
+ # if a multi-type join was needed in the subquery ("multi" is indicated by
+ # presence in {collapse}) - add a group_by to simulate the collapse in the subq
+ for my $alias (keys %inner_joins) {
+
+ # the dot comes from some weirdness in collapse
+ # remove after the rewrite
+ if ($attrs->{collapse}{".$alias"}) {
+ $sub_attrs->{group_by} = $sub_select;
+ last;
+ }
+ }
+ }
+
+ # generate the subquery
+ my $subq = $self->_select_args_to_query (
+ $inner_from,
+ $sub_select,
+ $where,
+ $sub_attrs
+ );
+
+ # put it back in $from
+ unshift @$from, { $alias => $subq };
+
+ # This is totally horrific - the $where ends up in both the inner and outer query
+ # Unfortunately not much can be done until SQLA2 introspection arrives
+ #
+ # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;)
+ return ($from, $select, $where, $attrs);
}
sub _resolve_ident_sources {
my $tmp_attrs = { %$attrs };
- # take off any pagers, record_filter is cdbi, and no point of ordering a count
- delete $tmp_attrs->{$_} for (qw/select as rows offset page order_by record_filter/);
+ # take off any limits, record_filter is cdbi, and no point of ordering a count
+ delete $tmp_attrs->{$_} for (qw/select as rows offset order_by record_filter/);
# overwrite the selector
$tmp_attrs->{select} = { count => '*' };
my $sub_attrs = { %$attrs };
# these can not go in the subquery, and there is no point of ordering it
- delete $sub_attrs->{$_} for qw/prefetch collapse select as order_by/;
+ delete $sub_attrs->{$_} for qw/collapse 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
# simply deleting group_by suffices, as the code below will re-fill it
}];
# the subquery replaces this
- delete $attrs->{$_} for qw/where bind prefetch collapse group_by having having_bind rows offset page pager/;
+ delete $attrs->{$_} for qw/where bind collapse group_by having having_bind rows offset/;
return $self->count ($source, $attrs);
}
$schema->default_resultset_attributes({ rows => 5 });
is($p->(), 5, 'default rows is 5');
+
+# test page with offset
+$it = $schema->resultset('CD')->search({}, {
+ rows => 2,
+ page => 2,
+ offset => 1,
+ order_by => 'cdid'
+});
+
+my $row = $schema->resultset('CD')->search({}, {
+ order_by => 'cdid',
+ offset => 3,
+ rows => 1
+})->single;
+
+is($row->cdid, $it->first->cdid, 'page with offset');
## Check that master_read_weight is honored
{
- no warnings 'once';
-
- # turn off redefined warning
- local $SIG{__WARN__} = sub {};
+ no warnings qw/once redefine/;
local
*DBIx::Class::Storage::DBI::Replicated::Balancer::Random::_random_number =
use DBICTest;
my $schema = DBICTest->init_schema();
-
# Under some versions of SQLite if the $rs is left hanging around it will lock
# So we create a scope here cos I'm lazy
{
});
$rs_hashrefinf->result_class('DBIx::Class::ResultClass::HashRefInflator');
is_deeply [$rs_hashrefinf->all], \@hashrefinf, 'Check query using extended columns syntax';
+
+# check nested prefetching of has_many relationships which return nothing
+my $artist = $schema->resultset ('Artist')->create ({ name => 'unsuccessful artist without CDs'});
+$artist->discard_changes;
+my $rs_artists = $schema->resultset ('Artist')->search ({ 'me.artistid' => $artist->id}, {
+ prefetch => { cds => 'tracks' }, result_class => 'DBIx::Class::ResultClass::HashRefInflator',
+});
+is_deeply(
+ [$rs_artists->all],
+ [{ $artist->get_columns, cds => [] }],
+ 'nested has_many prefetch without entries'
+);
my $schema = DBICTest->init_schema();
-my $orig_debug = $schema->storage->debug;
-
-use IO::File;
-
-BEGIN {
- eval "use DBD::SQLite";
- plan $@
- ? ( skip_all => 'needs DBD::SQLite for testing' )
- : ( tests => 3 );
-}
+plan tests => 3;
# bug in 0.07000 caused attr (join/prefetch) to be modifed by search
# so we check the search & attr arrays are not modified
--- /dev/null
+use warnings;
+
+use Test::More;
+use Test::Exception;
+use lib qw(t/lib);
+use DBIC::SqlMakerTest;
+use DBICTest;
+
+my $schema = DBICTest->init_schema();
+
+plan tests => 1;
+
+# While this is a rather GIGO case, make sure it behaves as pre-103,
+# as it may result in hard-to-track bugs
+my $cds = $schema->resultset('Artist')
+ ->search_related ('cds')
+ ->search ({}, {
+ prefetch => [ 'single_track', { single_track => 'cd' } ],
+ });
+
+is_same_sql(
+ ${$cds->as_query}->[0],
+ '(
+ SELECT
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
+ single_track.trackid, single_track.cd, single_track.position, single_track.title, single_track.last_updated_on, single_track.last_updated_at,
+ single_track_2.trackid, single_track_2.cd, single_track_2.position, single_track_2.title, single_track_2.last_updated_on, single_track_2.last_updated_at,
+ cd.cdid, cd.artist, cd.title, cd.year, cd.genreid, cd.single_track
+ FROM artist me
+ LEFT JOIN cd cds ON cds.artist = me.artistid
+ LEFT JOIN track single_track ON single_track.trackid = cds.single_track
+ LEFT JOIN track single_track_2 ON single_track_2.trackid = cds.single_track
+ LEFT JOIN cd cd ON cd.cdid = single_track_2.cd
+ )',
+);
+++ /dev/null
-# Test to ensure we get a consistent result set wether or not we use the
-# prefetch option in combination rows (LIMIT).
-use strict;
-use warnings;
-
-use Test::More;
-use lib qw(t/lib);
-use DBICTest;
-
-plan skip_all => 'fix pending';
-#plan tests => 4;
-
-my $schema = DBICTest->init_schema();
-my $no_prefetch = $schema->resultset('Artist')->search(
- undef,
- { rows => 3 }
-);
-
-my $use_prefetch = $schema->resultset('Artist')->search(
- undef,
- {
- prefetch => 'cds',
- rows => 3
- }
-);
-
-is($no_prefetch->count, $use_prefetch->count, '$no_prefetch->count == $use_prefetch->count');
-is(
- scalar ($no_prefetch->all),
- scalar ($use_prefetch->all),
- "Amount of returned rows is right"
-);
-
-
-
-my $artist_many_cds = $schema->resultset('Artist')->search ( {}, {
- join => 'cds',
- group_by => 'me.artistid',
- having => \ 'count(cds.cdid) > 1',
-})->first;
-
-
-$no_prefetch = $schema->resultset('Artist')->search(
- { artistid => $artist_many_cds->id },
- { rows => 1 }
-);
-
-$use_prefetch = $schema->resultset('Artist')->search(
- { artistid => $artist_many_cds->id },
- {
- prefetch => 'cds',
- rows => 1
- }
-);
-
-my $prefetch_artist = $use_prefetch->first;
-my $normal_artist = $no_prefetch->first;
-
-is(
- $prefetch_artist->cds->count,
- $normal_artist->cds->count,
- "Count of child rel with prefetch + rows => 1 is right"
-);
-is (
- scalar ($prefetch_artist->cds->all),
- scalar ($normal_artist->cds->all),
- "Amount of child rel rows with prefetch + rows => 1 is right"
-);
--- /dev/null
+# Test to ensure we get a consistent result set wether or not we use the
+# prefetch option in combination rows (LIMIT).
+use strict;
+use warnings;
+
+use Test::More;
+use Test::Exception;
+use lib qw(t/lib);
+use DBICTest;
+
+plan tests => 9;
+
+my $schema = DBICTest->init_schema();
+
+
+my $no_prefetch = $schema->resultset('Artist')->search(
+ undef,
+ { rows => 3 }
+);
+
+my $use_prefetch = $schema->resultset('Artist')->search(
+ [ # search deliberately contrived
+ { 'artwork.cd_id' => undef },
+ { 'tracks.title' => { '!=' => 'blah-blah-1234568' }}
+ ],
+ {
+ prefetch => 'cds',
+ join => { cds => [qw/artwork tracks/] },
+ rows => 3,
+ order_by => { -desc => 'name' },
+ }
+);
+
+is($no_prefetch->count, $use_prefetch->count, '$no_prefetch->count == $use_prefetch->count');
+is(
+ scalar ($no_prefetch->all),
+ scalar ($use_prefetch->all),
+ "Amount of returned rows is right"
+);
+
+my $artist_many_cds = $schema->resultset('Artist')->search ( {}, {
+ join => 'cds',
+ group_by => 'me.artistid',
+ having => \ 'count(cds.cdid) > 1',
+})->first;
+
+
+$no_prefetch = $schema->resultset('Artist')->search(
+ { artistid => $artist_many_cds->id },
+ { rows => 1 }
+);
+
+$use_prefetch = $no_prefetch->search ({}, { prefetch => 'cds' });
+
+my $normal_artist = $no_prefetch->single;
+my $prefetch_artist = $use_prefetch->find({ name => $artist_many_cds->name });
+my $prefetch2_artist = $use_prefetch->first;
+
+is(
+ $prefetch_artist->cds->count,
+ $normal_artist->cds->count,
+ "Count of child rel with prefetch + rows => 1 is right (find)"
+);
+is(
+ $prefetch2_artist->cds->count,
+ $normal_artist->cds->count,
+ "Count of child rel with prefetch + rows => 1 is right (first)"
+);
+
+is (
+ scalar ($prefetch_artist->cds->all),
+ scalar ($normal_artist->cds->all),
+ "Amount of child rel rows with prefetch + rows => 1 is right (find)"
+);
+is (
+ scalar ($prefetch2_artist->cds->all),
+ scalar ($normal_artist->cds->all),
+ "Amount of child rel rows with prefetch + rows => 1 is right (first)"
+);
+
+throws_ok (
+ sub { $use_prefetch->single },
+ qr/resultsets prefetching has_many/,
+ 'single() with multiprefetch is illegal',
+);
+
+my $artist = $use_prefetch->search({'cds.title' => $artist_many_cds->cds->first->title })->next;
+is($artist->cds->count, 1, "count on search limiting prefetched has_many");
+
+# try with double limit
+my $artist2 = $use_prefetch->search({'cds.title' => { '!=' => $artist_many_cds->cds->first->title } })->slice (0,0)->next;
+is($artist2->cds->count, 2, "count on search limiting prefetched has_many");
+
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