X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits%2FDBIx-Class.git;a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=c6935c35c2a9866577a092bf3b9a956f142e87cd;hp=71595e3ac386f7604a63147c2b54b1e313ae821d;hb=d71502b;hpb=2268474f6427676f69515a0ea47d638eaa6b497c diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index 71595e3..c6935c3 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -4,9 +4,8 @@ use strict; use warnings; use base qw/DBIx::Class/; use DBIx::Class::Carp; -use DBIx::Class::Exception; 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 @@ -26,6 +25,10 @@ use overload '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 @@ -34,12 +37,12 @@ DBIx::Class::ResultSet - Represents a query used for fetching a set of results. =head1 SYNOPSIS - my $users_rs = $schema->resultset('User'); + my $users_rs = $schema->resultset('User'); while( $user = $users_rs->next) { print $user->username; } - my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 }); + my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 }); my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all(); =head1 DESCRIPTION @@ -138,11 +141,15 @@ another. =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: +Csearch(\%extra_cond, \%attrs)>), conditions +and attributes with the same keys need resolving. -L, L, L, L attributes are merged -into the existing ones from the original resultset. +If any of L, L, L are present, they reset the +original selection, and start the selection "clean". + +The L, L, L, L, L attributes +are merged into the existing ones from the original resultset. The L and L attributes, and any search conditions, are merged with an SQL C to the existing condition from the original @@ -191,9 +198,9 @@ See: L, L, L, L, L. =over 4 -=item Arguments: $source, \%$attrs +=item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES> -=item Return Value: $rs +=item Return Value: L<$resultset|/search> =back @@ -202,16 +209,31 @@ L) and an attribute hash (see L below). Does not perform any queries -- these are executed as needed by the other methods. -Generally you won't need to construct a resultset manually. You'll -automatically get one from e.g. a L called in scalar context: +Generally you never construct a resultset manually. Instead you get one +from e.g. a +C<< $schema->L('$source_name') >> +or C<< $another_resultset->L(...) >> (the later called in +scalar context): my $rs = $schema->resultset('CD')->search({ title => '100th Window' }); -IMPORTANT: If called on an object, proxies to new_result instead so +=over + +=item WARNING + +If called on an object, proxies to L instead, so my $cd = $schema->resultset('CD')->new({ title => 'Spoon' }); -will return a CD object, not a ResultSet. +will return a CD object, not a ResultSet, and is equivalent to: + + my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' }); + +Please also keep in mind that many internals call L directly, +so overloading this method with the idea of intercepting new result object +creation B. See also warning pertaining to L. + +=back =cut @@ -222,7 +244,9 @@ sub new { my ($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; @@ -254,9 +278,9 @@ sub new { =over 4 -=item Arguments: $cond, \%attrs? +=item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES> -=item Return Value: $resultset (scalar context) || @row_objs (list context) +=item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context) =back @@ -267,7 +291,8 @@ sub new { # year = 2005 OR year = 2004 In list context, C<< ->all() >> is called implicitly on the resultset, thus -returning a list of row objects instead. To avoid that, use L. +returning a list of L objects instead. +To avoid that, use L. If you need to pass in additional attributes but no additional condition, call it as C. @@ -280,7 +305,7 @@ call it as C. For a list of attributes that can be passed to C, see L. For more examples of using this function, see L. For a complete -documentation for the first argument, see L +documentation for the first argument, see L and its extension L. For more help on using joins with search, see L. @@ -289,7 +314,7 @@ For more help on using joins with search, see L. Note that L does not process/deflate any of the values passed in the L-compatible search condition structure. This is unlike other -condition-bound methods L, L and L. The user must ensure +condition-bound methods L, L and L. The user must ensure manually that any value passed to this method will stringify to something the RDBMS knows how to deal with. A notable example is the handling of L objects, for more info see: @@ -324,9 +349,9 @@ sub search { =over 4 -=item Arguments: $cond, \%attrs? +=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES> -=item Return Value: $resultset +=item Return Value: L<$resultset|/search> =back @@ -338,45 +363,61 @@ always return a resultset, even in list context. sub search_rs { my $self = shift; - # Special-case handling for (undef, undef). - if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) { - @_ = (); - } + my $rsrc = $self->result_source; + my ($call_cond, $call_attrs); - my $call_attrs = {}; - if (@_ > 1) { - if (ref $_[-1] eq 'HASH') { - # copy for _normalize_selection - $call_attrs = { %{ pop @_ } }; - } - elsif (! defined $_[-1] ) { - pop @_; # search({}, undef) + # Special-case handling for (undef, undef) or (undef) + # Note that (foo => undef) is valid deprecated syntax + @_ = () if not scalar grep { defined $_ } @_; + + # just a cond + if (@_ == 1) { + $call_cond = shift; + } + # fish out attrs in the ($condref, $attr) case + elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) { + ($call_cond, $call_attrs) = @_; + } + elsif (@_ % 2) { + $self->throw_exception('Odd number of arguments to search') + } + # legacy search + elsif (@_) { + carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead' + unless $rsrc->result_class->isa('DBIx::Class::CDBICompat'); + + for my $i (0 .. $#_) { + next if $i % 2; + $self->throw_exception ('All keys in condition key/value pairs must be plain scalars') + if (! defined $_[$i] or ref $_[$i] ne ''); } + + $call_cond = { @_ }; } # see if we can keep the cache (no $rs changes) 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 $rsrc = $self->result_source; - 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 }; # take care of call attrs (only if anything is changing) - if (keys %$call_attrs) { + if ($call_attrs and keys %$call_attrs) { + + # copy for _normalize_selection + $call_attrs = { %$call_attrs }; my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/; @@ -403,6 +444,7 @@ sub search_rs { # 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'"; } @@ -423,28 +465,6 @@ sub search_rs { } - # rip apart the rest of @_, parse a condition - my $call_cond = do { - - if (ref $_[0] eq 'HASH') { - (keys %{$_[0]}) ? $_[0] : undef - } - elsif (@_ == 1) { - $_[0] - } - elsif (@_ % 2) { - $self->throw_exception('Odd number of arguments to search') - } - else { - +{ @_ } - } - - } if @_; - - if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) { - carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'; - } - for ($old_where, $call_cond) { if (defined $_) { $new_attrs->{where} = $self->_stack_cond ( @@ -471,8 +491,12 @@ sub _normalize_selection { my ($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 @@ -617,11 +641,20 @@ sub _stack_cond { =head2 search_literal +B: C is provided for Class::DBI compatibility and +should only be used in that context. C is a convenience +method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you +want to ensure columns are bound correctly, use L. + +See L and +L for searching techniques that do not +require C. + =over 4 -=item Arguments: $sql_fragment, @bind_values +=item Arguments: $sql_fragment, @standalone_bind_values -=item Return Value: $resultset (scalar context) || @row_objs (list context) +=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context) =back @@ -631,21 +664,11 @@ sub _stack_cond { Pass a literal chunk of SQL to be added to the conditional part of the resultset query. -CAVEAT: C is provided for Class::DBI compatibility and should -only be used in that context. C is a convenience method. -It is equivalent to calling $schema->search(\[]), but if you want to ensure -columns are bound correctly, use C. - Example of how to use C instead of C my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2)); my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]); - -See L and -L for searching techniques that do not -require C. - =cut sub search_literal { @@ -654,16 +677,16 @@ sub search_literal { if ( @bind && ref($bind[-1]) eq 'HASH' ) { $attr = pop @bind; } - return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () )); + return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () )); } =head2 find =over 4 -=item Arguments: \%columns_values | @pk_values, \%attrs? +=item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }? -=item Return Value: $row_object | undef +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef =back @@ -695,7 +718,7 @@ Note that this fallback behavior may be deprecated in further versions. If you need to search with arbitrary conditions - use L. If the query resulting from this fallback produces more than one row, a warning to the effect is issued, though only the first row is constructed and returned as -C<$row_object>. +C<$result_object>. In addition to C, L recognizes and applies standard L in the same way as L does. @@ -829,7 +852,7 @@ sub find { # Run the query, passing the result_class since it should propagate for find my $rs = $self->search ($final_cond, {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 $row; @@ -909,7 +932,7 @@ sub _build_unique_cond { and !$ENV{DBIC_NULLABLE_KEY_NOWARN} and - my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond) + my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond) ) { carp_unique ( sprintf ( "NULL/undef values supplied for requested unique constraint '%s' (NULL " @@ -927,9 +950,9 @@ sub _build_unique_cond { =over 4 -=item Arguments: $rel, $cond?, \%attrs? +=item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES> -=item Return Value: $new_resultset (scalar context) || @row_objs (list context) +=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context) =back @@ -941,7 +964,7 @@ Searches the specified relationship, optionally specifying a condition and attributes for matching records. See L for more information. In list context, C<< ->all() >> is called implicitly on the resultset, thus -returning a list of row objects instead. To avoid that, use L. +returning a list of result objects instead. To avoid that, use L. See also L. @@ -968,7 +991,7 @@ sub search_related_rs { =item Arguments: none -=item Return Value: $cursor +=item Return Value: L<$cursor|DBIx::Class::Cursor> =back @@ -978,22 +1001,23 @@ L for more information. =cut sub cursor { - my ($self) = @_; - - my $attrs = $self->_resolved_attrs_copy; + my $self = shift; - return $self->{cursor} - ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select}, - $attrs->{where},$attrs); + return $self->{cursor} ||= do { + my $attrs = $self->_resolved_attrs; + $self->result_source->storage->select( + $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs + ); + }; } =head2 single =over 4 -=item Arguments: $cond? +=item Arguments: L<$cond?|DBIx::Class::SQLMaker> -=item Return Value: $row_object | undef +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef =back @@ -1036,13 +1060,11 @@ sub single { $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()'); } - my $attrs = $self->_resolved_attrs_copy; + my $attrs = { %{$self->_resolved_attrs} }; - if (keys %{$attrs->{collapse}}) { - $self->throw_exception( - 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead' - ); - } + $self->throw_exception( + 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead' + ) if $attrs->{collapse}; if ($where) { if (defined $attrs->{where}) { @@ -1056,12 +1078,14 @@ sub single { } } - my @data = $self->result_source->storage->select_single( + my $data = [ $self->result_source->storage->select_single( $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs - ); + )]; - return (@data ? ($self->_construct_object(@data))[0] : undef); + return undef unless @$data; + $self->{_stashed_rows} = [ $data ]; + $self->_construct_results->[0]; } @@ -1101,9 +1125,9 @@ sub _collapse_query { =over 4 -=item Arguments: $cond? +=item Arguments: L<$cond?|DBIx::Class::SQLMaker> -=item Return Value: $resultsetcolumn +=item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn> =back @@ -1123,9 +1147,9 @@ sub get_column { =over 4 -=item Arguments: $cond, \%attrs? +=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES> -=item Return Value: $resultset (scalar context) || @row_objs (list context) +=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context) =back @@ -1168,7 +1192,7 @@ sub search_like { =item Arguments: $first, $last -=item Return Value: $resultset (scalar context) || @row_objs (list context) +=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context) =back @@ -1197,7 +1221,7 @@ sub slice { =item Arguments: none -=item Return Value: $result | undef +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef =back @@ -1218,170 +1242,292 @@ first record from the resultset. sub next { my ($self) = @_; + if (my $cache = $self->get_cache) { $self->{all_cache_position} ||= 0; return $cache->[$self->{all_cache_position}++]; } + if ($self->{attrs}{cache}) { delete $self->{pager}; $self->{all_cache_position} = 1; return ($self->all)[0]; } - if ($self->{stashed_objects}) { - my $obj = shift(@{$self->{stashed_objects}}); - delete $self->{stashed_objects} unless @{$self->{stashed_objects}}; - return $obj; - } - my @row = ( - exists $self->{stashed_row} - ? @{delete $self->{stashed_row}} - : $self->cursor->next - ); - return undef unless (@row); - my ($row, @more) = $self->_construct_object(@row); - $self->{stashed_objects} = \@more if @more; - return $row; -} -sub _construct_object { - my ($self, @row) = @_; + return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] }; - 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}; - return @new; -} + $self->{_stashed_results} = $self->_construct_results + or return undef; -sub _collapse_result { - my ($self, $as_proto, $row) = @_; + return shift @{$self->{_stashed_results}}; +} - my @copy = @$row; +# Constructs as many results as it can in one pass while respecting +# cursor laziness. Several modes of operation: +# +# * Always builds everything present in @{$self->{_stashed_rows}} +# * If called with $fetch_all true - pulls everything off the cursor and +# 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}} +# OR +# * Just fetches, and collapses/constructs everything as if $fetch_all +# was requested (there is no other way to collapse except for an +# eager cursor) +# * If no collapse is requested - just get the next row, construct and +# return +sub _construct_results { + my ($self, $fetch_all) = @_; - # 'foo' => [ undef, 'foo' ] - # 'foo.bar' => [ 'foo', 'bar' ] - # 'foo.bar.baz' => [ 'foo.bar', 'baz' ] + my $rsrc = $self->result_source; + my $attrs = $self->_resolved_attrs; - my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto; + 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; + $attrs->{_order_is_artificial} = 1; + } - my %collapse = %{$self->{_attrs}{collapse}||{}}; + # this will be used as both initial raw-row collector AND as a RV of + # _construct_results. Not regrowing the array twice matters a lot... + # a surprising amount actually + my $rows = delete $self->{_stashed_rows}; - my @pri_index; + my $cursor; # we may not need one at all - # if we're doing collapsing (has_many prefetch) we need to grab records - # until the PK changes, so fill @pri_index. if not, we leave it empty so - # we know we don't have to bother. + my $did_fetch_all = $fetch_all; - # the reason for not using the collapse stuff directly is because if you - # had for e.g. two artists in a row with no cds, the collapse info for - # both would be NULL (undef) so you'd lose the second artist + if ($fetch_all) { + # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref + $rows = [ ($rows ? @$rows : ()), $self->cursor->all ]; + } + elsif( $attrs->{collapse} ) { - # store just the index so we can check the array positions from the row - # without having to contruct the full hash + # a cursor will need to be closed over in case of collapse + $cursor = $self->cursor; - if (keys %collapse) { - my %pri = map { ($_ => 1) } $self->result_source->_pri_cols; - foreach my $i (0 .. $#construct_as) { - next if defined($construct_as[$i][0]); # only self table - if (delete $pri{$construct_as[$i][1]}) { - push(@pri_index, $i); + $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; } - last unless keys %pri; # short circuit (Johnny Five Is Alive!) } } - # no need to do an if, it'll be empty if @pri_index is empty anyway + if (! $did_fetch_all and ! @{$rows||[]} ) { + # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref + $cursor ||= $self->cursor; + if (scalar (my @r = $cursor->next) ) { + $rows = [ \@r ]; + } + } - my %pri_vals = map { ($_ => $copy[$_]) } @pri_index; + return undef unless @{$rows||[]}; - my @const_rows; + # sanity check - people are too clever for their own good + if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) { - do { # no need to check anything at the front, we always want the first row + 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}} + } + } + + for my $i (0 .. $#{$attrs->{as}} ) { + my $sel = $attrs->{select}[$i]; - my %const; + if (ref $sel eq 'SCALAR') { + $sel = $$sel; + } + elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) { + $sel = $$sel->[0]; + } - foreach my $this_as (@construct_as) { - $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy); + $self->throw_exception( + 'Result collapse not possible - selection from a has_many source redirected to the main object' + ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./); } + } - push(@const_rows, \%const); + # hotspot - skip the setter + my $res_class = $self->_result_class; - } until ( # no pri_index => no collapse => drop straight out - !@pri_index - or - do { # get another row, stash it, drop out if different PK + 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"); + }; - @copy = $self->cursor->next; - $self->{stashed_row} = \@copy; + my $infmap = $attrs->{as}; - # last thing in do block, counts as true if anything doesn't match + $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}; - # check xor defined first for NULL vs. NOT NULL then if one is - # defined the other must be so check string equality - grep { - (defined $pri_vals{$_} ^ defined $copy[$_]) - || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_])) - } @pri_index; + 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::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 + elsif (@$rows < 60) { + for my $r (@$rows) { + $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } ); + } + } + else { + eval sprintf ( + '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows', + join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap ) + ); + } + } + else { + my $parser_type = + $self->{_result_inflator}{is_hri} ? 'hri' + : $self->{_result_inflator}{is_core_row} ? 'classic_pruning' + : 'classic_nonpruning' + ; - my $alias = $self->{attrs}{alias}; - my $info = []; + # $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, + collapse => $attrs->{collapse}, + premultiplied => $attrs->{_main_source_premultiplied}, + 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); - my %collapse_pos; + if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) { - my @const_keys; + $err = + 'Collapse aborted due to invalid ResultSource metadata - the following ' + . 'selections are declared non-nullable but NULLs were retrieved: ' + ; - foreach my $const (@const_rows) { - scalar @const_keys or do { - @const_keys = sort { length($a) <=> length($b) } keys %$const; - }; - foreach my $key (@const_keys) { - if (length $key) { - my $target = $info; - my @parts = split(/\./, $key); - my $cur = ''; - my $data = $const->{$key}; - foreach my $p (@parts) { - $target = $target->[1]->{$p} ||= []; - $cur .= ".${p}"; - if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) { - # collapsing at this point and on final part - my $pos = $collapse_pos{$cur}; - CK: foreach my $ck (@ckey) { - if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) { - $collapse_pos{$cur} = $data; - delete @collapse_pos{ # clear all positioning for sub-entries - grep { m/^\Q${cur}.\E/ } keys %collapse_pos - }; - push(@$target, []); - last CK; - } - } - } - if (exists $collapse{$cur}) { - $target = $target->[-1]; - } - } - $target->[0] = $data; - } else { - $info->[0] = $const->{$key}; + 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); } + + 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 + } + ; + + $self->{_row_parser}{$parser_type}{cref}->( + $rows, + $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (), + ); - return $info; + # 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; } =head2 result_source =over 4 -=item Arguments: $result_source? +=item Arguments: L<$result_source?|DBIx::Class::ResultSource> -=item Return Value: $result_source +=item Return Value: L<$result_source|DBIx::Class::ResultSource> =back @@ -1398,7 +1544,7 @@ is derived. =back -An accessor for the class to use when creating row objects. Defaults to +An accessor for the class to use when creating result objects. Defaults to C<< result_source->result_class >> - which in most cases is the name of the L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class. @@ -1412,14 +1558,22 @@ in the original source class will not run. 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; } @@ -1428,7 +1582,7 @@ sub result_class { =over 4 -=item Arguments: $cond, \%attrs?? +=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES> =item Return Value: $count @@ -1445,12 +1599,11 @@ sub count { return $self->search(@_)->count if @_ and defined $_[0]; return scalar @{ $self->get_cache } if $self->get_cache; - my $attrs = $self->_resolved_attrs_copy; + my $attrs = { %{ $self->_resolved_attrs } }; # this is a little optimization - it is faster to do the limit # adjustments in software, instead of a subquery - my $rows = delete $attrs->{rows}; - my $offset = delete $attrs->{offset}; + my ($rows, $offset) = delete @{$attrs}{qw/rows offset/}; my $crs; if ($self->_has_resolved_attr (qw/collapse group_by/)) { @@ -1472,9 +1625,9 @@ sub count { =over 4 -=item Arguments: $cond, \%attrs?? +=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES> -=item Return Value: $count_rs +=item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn> =back @@ -1498,10 +1651,10 @@ sub count_rs { # 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}); } } @@ -1512,20 +1665,17 @@ sub _count_rs { 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); - $tmp_attrs->{as} = 'count'; - delete @{$tmp_attrs}{qw/columns/}; - - 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, $attrs), + as => 'count', + })->get_column ('count'); } # @@ -1535,15 +1685,14 @@ sub _count_subq_rs { my ($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 - if ( keys %{$attrs->{collapse}} ) { + if ( $attrs->{collapse} ) { $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{ $rsrc->_identifying_column_set || $self->throw_exception( 'Unable to construct a unique group_by criteria properly collapsing the ' @@ -1581,18 +1730,22 @@ sub _count_subq_rs { my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); - my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }); + my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }); + my %seen_having; # search for both a proper quoted qualified string, for a naive unquoted scalarref # and if all fails for an utterly naive quoted scalar-with-function - while ($sql =~ / + while ($having_sql =~ / $rquote $sep $lquote (.+?) $rquote | [\s,] \w+ \. (\w+) [\s,] | [\s,] $lquote (.+?) $rquote [\s,] /gx) { - push @parts, ($1 || $2 || $3); # one of them matched if we got here + my $part = $1 || $2 || $3; # one of them matched if we got here + unless ($seen_having{$part}++) { + push @parts, $part; + } } } @@ -1622,15 +1775,15 @@ sub _count_subq_rs { ->get_column ('count'); } -sub _bool { - return 1; -} =head2 count_literal +B: C is provided for Class::DBI compatibility and +should only be used in that context. See L for further info. + =over 4 -=item Arguments: $sql_fragment, @bind_values +=item Arguments: $sql_fragment, @standalone_bind_values =item Return Value: $count @@ -1649,7 +1802,7 @@ sub count_literal { shift->search_literal(@_)->count; } =item Arguments: none -=item Return Value: @objects +=item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass> =back @@ -1660,33 +1813,22 @@ Returns all elements in the resultset. sub all { my $self = shift; if(@_) { - $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()"); + $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()"); } - return @{ $self->get_cache } if $self->get_cache; - - my @obj; - - if (keys %{$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 - $self->cursor->reset; - my @row = $self->cursor->next; - while (@row) { - push(@obj, $self->_construct_object(@row)); - @row = (exists $self->{stashed_row} - ? @{delete $self->{stashed_row}} - : $self->cursor->next); - } - } else { - @obj = map { $self->_construct_object(@$_) } $self->cursor->all; + delete @{$self}{qw/_stashed_rows _stashed_results/}; + + if (my $c = $self->get_cache) { + return @$c; } - $self->set_cache(\@obj) if $self->{attrs}{cache}; + $self->cursor->reset; + + my $objs = $self->_construct_results('fetch_all') || []; + + $self->set_cache($objs) if $self->{attrs}{cache}; - return @obj; + return @$objs; } =head2 reset @@ -1707,7 +1849,8 @@ another query. sub reset { my ($self) = @_; - delete $self->{_attrs} if exists $self->{_attrs}; + + delete @{$self}{qw/_stashed_rows _stashed_results/}; $self->{all_cache_position} = 0; $self->cursor->reset; return $self; @@ -1719,12 +1862,12 @@ sub reset { =item Arguments: none -=item Return Value: $object | undef +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef =back -Resets the resultset and returns an object for the first result (or C -if the resultset is empty). +L the resultset (causing a fresh query to storage) and returns +an object for the first result (or C if the resultset is empty). =cut @@ -1742,154 +1885,141 @@ sub first { sub _rs_update_delete { my ($self, $op, $values) = @_; - my $cond = $self->{cond}; my $rsrc = $self->result_source; my $storage = $rsrc->schema->storage; my $attrs = { %{$self->_resolved_attrs} }; - # "needs" is a strong word here - if the subquery is part of an IN clause - no point of - # even adding the group_by. It will really be used only when composing a poor-man's - # multicolumn-IN equivalent OR set - my $needs_group_by_subq = defined $attrs->{group_by}; - - # simplify the joinmap and maybe decide if a grouping (and thus subquery) is necessary - my $relation_classifications; - if (ref($attrs->{from}) eq 'ARRAY') { - $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs); - - $relation_classifications = $storage->_resolve_aliastypes_from_select_args ( - [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ], - $attrs->{select}, - $cond, - $attrs - ) unless $needs_group_by_subq; # we already know we need a group, no point of resolving them - } - else { - $needs_group_by_subq ||= 1; # if {from} is unparseable assume the worst - } + my $join_classifications; + my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)}; - $needs_group_by_subq ||= exists $relation_classifications->{multiplying}; - - # if no subquery - life is easy-ish - unless ( - $needs_group_by_subq + # do we need a subquery for any reason? + my $needs_subq = ( + defined $existing_group_by or - keys %$relation_classifications # if any joins at all - need to wrap a subq + # if {from} is unparseable wrap a subq + ref($attrs->{from}) ne 'ARRAY' or - $self->_has_resolved_attr(qw/rows offset/) # limits call for a subq - ) { - # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus - # a condition containing 'me' or other table prefixes will not work - # at all. What this code tries to do (badly) is to generate a condition - # with the qualifiers removed, by exploiting the quote mechanism of sqla - # - # this is atrocious and should be replaced by normal sqla introspection - # one sunny day - my ($sql, @bind) = do { - my $sqla = $rsrc->storage->sql_maker; - local $sqla->{_dequalify_idents} = 1; - $sqla->_recurse_where($self->{cond}); - } if $self->{cond}; + # limits call for a subq + $self->_has_resolved_attr(qw/rows offset/) + ); - return $rsrc->storage->$op( - $rsrc, - $op eq 'update' ? $values : (), - $self->{cond} ? \[$sql, @bind] : (), - ); + # simplify the joinmap, so we can further decide if a subq is necessary + if (!$needs_subq and @{$attrs->{from}} > 1) { + + ($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} || {} }; } - # we got this far - means it is time to wrap a subquery - my $idcols = $rsrc->_identifying_column_set || $self->throw_exception( - sprintf( - "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'", - $op, - $rsrc->source_name, - ) + # check if the head is composite (by now all joins are thrown out unless $needs_subq) + $needs_subq ||= ( + (ref $attrs->{from}[0]) ne 'HASH' + or + ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} } ); - my $existing_group_by = delete $attrs->{group_by}; - - # make a new $rs selecting only the PKs (that's all we really need for the subq) - delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/; - $attrs->{columns} = [ map { "$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 - my $subrs = (ref $self)->new($rsrc, $attrs); - if (@$idcols == 1) { - return $storage->$op ( - $rsrc, - $op eq 'update' ? $values : (), - { $idcols->[0] => { -in => $subrs->as_query } }, - ); + my ($cond, $guard); + # do we need anything like a subquery? + if (! $needs_subq) { + # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus + # a condition containing 'me' or other table prefixes will not work + # at all. Tell SQLMaker to dequalify idents via a gross hack. + $cond = do { + my $sqla = $rsrc->storage->sql_maker; + local $sqla->{_dequalify_idents} = 1; + \[ $sqla->_recurse_where($self->{cond}) ]; + }; } - elsif ($storage->_use_multicolumn_in) { - # This is hideously ugly, but SQLA does not understand multicol IN expressions - my $sql_maker = $storage->sql_maker; - my ($sql, @bind) = @${$subrs->as_query}; - $sql = sprintf ('(%s) IN %s', # the as_query already comes with a set of parenthesis - join (', ', map { $sql_maker->_quote ($_) } @$idcols), - $sql, + else { + # we got this far - means it is time to wrap a subquery + my $idcols = $rsrc->_identifying_column_set || $self->throw_exception( + sprintf( + "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'", + $op, + $rsrc->source_name, + ) ); - return $storage->$op ( - $rsrc, - $op eq 'update' ? $values : (), - \[$sql, @bind], - ); - } - else { - # if all else fails - get all primary keys and operate over a ORed set - # wrap in a transaction for consistency - # this is where the group_by starts to matter - my $subq_group_by; - if ($needs_group_by_subq) { - $subq_group_by = $attrs->{columns}; - - # make sure if there is a supplied group_by it matches the columns compiled above - # perfectly. Anything else can not be sanely executed on most databases so croak - # right then and there - if ($existing_group_by) { - my @current_group_by = map - { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" } - @$existing_group_by - ; + # make a new $rs selecting only the PKs (that's all we really need for the subq) + delete $attrs->{$_} for qw/select as collapse/; + $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ]; - if ( - join ("\x00", sort @current_group_by) - ne - join ("\x00", sort @$subq_group_by ) - ) { - $self->throw_exception ( - "You have just attempted a $op operation on a resultset which does group_by" - . ' on columns other than the primary keys, while DBIC internally needs to retrieve' - . ' the primary keys in a subselect. All sane RDBMS engines do not support this' - . ' kind of queries. Please retry the operation with a modified group_by or' - . ' without using one at all.' - ); + # 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) { + $cond = { $idcols->[0] => { -in => $subrs->as_query } }; + } + elsif ($storage->_use_multicolumn_in) { + # no syntax for calling this properly yet + # !!! EXPERIMENTAL API !!! WILL CHANGE !!! + $cond = $storage->sql_maker->_where_op_multicolumn_in ( + $idcols, # how do I convey a list of idents...? can binds reside on lhs? + $subrs->as_query + ), + } + else { + # if all else fails - get all primary keys and operate over a ORed set + # wrap in a transaction for consistency + # this is where the group_by/multiplication starts to matter + if ( + $existing_group_by + or + keys %{ $join_classifications->{multiplying} || {} } + ) { + # make sure if there is a supplied group_by it matches the columns compiled above + # perfectly. Anything else can not be sanely executed on most databases so croak + # right then and there + if ($existing_group_by) { + my @current_group_by = map + { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" } + @$existing_group_by + ; + + if ( + join ("\x00", sort @current_group_by) + ne + join ("\x00", sort @{$attrs->{columns}} ) + ) { + $self->throw_exception ( + "You have just attempted a $op operation on a resultset which does group_by" + . ' on columns other than the primary keys, while DBIC internally needs to retrieve' + . ' the primary keys in a subselect. All sane RDBMS engines do not support this' + . ' kind of queries. Please retry the operation with a modified group_by or' + . ' without using one at all.' + ); + } } + + $subrs = $subrs->search({}, { group_by => $attrs->{columns} }); } - } - my $guard = $storage->txn_scope_guard; + $guard = $storage->txn_scope_guard; - my @op_condition; - for my $row ($subrs->search({}, { group_by => $subq_group_by })->cursor->all) { - push @op_condition, { map - { $idcols->[$_] => $row->[$_] } - (0 .. $#$idcols) - }; + $cond = []; + for my $row ($subrs->cursor->all) { + push @$cond, { map + { $idcols->[$_] => $row->[$_] } + (0 .. $#$idcols) + }; + } } + } - my $res = $storage->$op ( - $rsrc, - $op eq 'update' ? $values : (), - \@op_condition, - ); + my $res = $storage->$op ( + $rsrc, + $op eq 'update' ? $values : (), + $cond, + ); - $guard->commit; + $guard->commit if $guard; - return $res; - } + return $res; } =head2 update @@ -1898,13 +2028,13 @@ sub _rs_update_delete { =item Arguments: \%values -=item Return Value: $storage_rv +=item Return Value: $underlying_storage_rv =back Sets the specified columns in the resultset to the supplied values in a single query. Note that this will not run any accessor/set_column/update -triggers, nor will it update any row object instances derived from this +triggers, nor will it update any result object instances derived from this resultset (this includes the contents of the L if any). See L if you need to execute any on-update triggers or cascades defined either by you or a @@ -1966,13 +2096,13 @@ sub update_all { =item Arguments: none -=item Return Value: $storage_rv +=item Return Value: $underlying_storage_rv =back Deletes the rows matching this resultset in a single query. Note that this will not run any delete triggers, nor will it alter the -L status of any row object instances +L status of any result object instances derived from this resultset (this includes the contents of the L if any). See L if you need to execute any on-delete triggers or cascades defined either by you or a @@ -2022,28 +2152,55 @@ sub delete_all { =over 4 -=item Arguments: \@data; +=item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ] + +=item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context) =back -Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs. -For the arrayref of hashrefs style each hashref should be a structure suitable -for submitting to a $resultset->create(...) method. +Accepts either an arrayref of hashrefs or alternatively an arrayref of +arrayrefs. + +=over + +=item NOTE + +The context of this method call has an important effect on what is +submitted to storage. In void context data is fed directly to fastpath +insertion routines provided by the underlying storage (most often +L), bypassing the L and +L calls on the +L class, including any +augmentation of these methods provided by components. For example if you +are using something like L to create primary +keys for you, you will find that your PKs are empty. In this case you +will have to explicitly force scalar or list context in order to create +those values. + +=back -In void context, C in L is used -to insert the data, as this is a faster method. +In non-void (scalar or list) context, this method is simply a wrapper +for L. Depending on list or scalar context either a list of +L objects or an arrayref +containing these objects is returned. -Otherwise, each set of data is inserted into the database using -L, and the resulting objects are -accumulated into an array. The array itself, or an array reference -is returned depending on scalar or list context. +When supplying data in "arrayref of arrayrefs" invocation style, the +first element should be a list of column names and each subsequent +element should be a data value in the earlier specified column order. +For example: -Example: Assuming an Artist Class that has many CDs Classes relating: + $Arstist_rs->populate([ + [ qw( artistid name ) ], + [ 100, 'A Formally Unknown Singer' ], + [ 101, 'A singer that jumped the shark two albums ago' ], + [ 102, 'An actually cool singer' ], + ]); - my $Artist_rs = $schema->resultset("Artist"); +For the arrayref of hashrefs style each hashref should be a structure +suitable for passing to L. Multi-create is also permitted with +this syntax. - ## Void Context Example - $Artist_rs->populate([ + $schema->resultset("Artist")->populate([ { artistid => 4, name => 'Manufactured Crap', cds => [ { title => 'My First CD', year => 2006 }, { title => 'Yet More Tweeny-Pop crap', year => 2007 }, @@ -2057,37 +2214,11 @@ Example: Assuming an Artist Class that has many CDs Classes relating: }, ]); - ## Array Context Example - my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([ - { name => "Artist One"}, - { name => "Artist Two"}, - { name => "Artist Three", cds=> [ - { title => "First CD", year => 2007}, - { title => "Second CD", year => 2008}, - ]} - ]); - - print $ArtistOne->name; ## response is 'Artist One' - print $ArtistThree->cds->count ## reponse is '2' - -For the arrayref of arrayrefs style, the first element should be a list of the -fieldsnames to which the remaining elements are rows being inserted. For -example: - - $Arstist_rs->populate([ - [qw/artistid name/], - [100, 'A Formally Unknown Singer'], - [101, 'A singer that jumped the shark two albums ago'], - [102, 'An actually cool singer'], - ]); - -Please note an important effect on your data when choosing between void and -wantarray context. Since void context goes straight to C in -L this will skip any component that is overriding -C. So if you are using something like L to -create primary keys for you, you will find that your PKs are empty. In this -case you will have to use the wantarray context in order to create those -values. +If you attempt a void-context multi-create as in the example above (each +Artist also has the related list of CDs), and B supply the +necessary autoinc foreign key information, this method will proxy to the +less efficient L, and then throw the Result objects away. In this +case there are obviously no benefits to using this method over L. =cut @@ -2100,10 +2231,7 @@ sub populate { return unless @$data; if(defined wantarray) { - my @created; - foreach my $item (@$data) { - push(@created, $self->create($item)); - } + my @created = map { $self->create($_) } @$data; return wantarray ? @created : \@created; } else { @@ -2158,14 +2286,12 @@ sub populate { ## inherit the data locked in the conditions of the resultset my ($rs_data) = $self->_merge_with_rscond({}); delete @{$rs_data}{@columns}; - my @inherit_cols = keys %$rs_data; - my @inherit_data = values %$rs_data; ## do bulk insert on current row $rsrc->storage->insert_bulk( $rsrc, - [@columns, @inherit_cols], - [ map { [ @$_{@columns}, @inherit_data ] } @$data ], + [@columns, keys %$rs_data], + [ map { [ @$_{@columns}, values %$rs_data ] } @$data ], ); ## do the has_many relationships @@ -2228,11 +2354,11 @@ sub _normalize_populate_args { =item Arguments: none -=item Return Value: $pager +=item Return Value: L<$pager|Data::Page> =back -Return Value a L object for the current resultset. Only makes +Returns a L object for the current resultset. Only makes sense for queries with a C attribute. To get the full count of entries for a paged resultset, call @@ -2257,7 +2383,7 @@ sub pager { # throw away the paging flags and re-run the count (possibly # with a subselect) to get the real total count my $count_attrs = { %$attrs }; - delete $count_attrs->{$_} for qw/rows offset page pager/; + delete @{$count_attrs}{qw/rows offset page pager/}; my $total_rs = (ref $self)->new($self->result_source, $count_attrs); @@ -2275,7 +2401,7 @@ sub pager { =item Arguments: $page_number -=item Return Value: $rs +=item Return Value: L<$resultset|/search> =back @@ -2294,16 +2420,16 @@ sub page { =over 4 -=item Arguments: \%vals +=item Arguments: \%col_data -=item Return Value: $rowobject +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> =back -Creates a new row object in the resultset's result class and returns +Creates a new result object in the resultset's result class and returns it. The row is not inserted into the database at this point, call L to do that. Calling L -will tell you whether the row object has been inserted or not. +will tell you whether the result object has been inserted or not. Passes the hashref of input on to L. @@ -2311,20 +2437,38 @@ Passes the hashref of input on to L. sub new_result { my ($self, $values) = @_; - $self->throw_exception( "new_result needs a hash" ) + + $self->throw_exception( "new_result takes only one argument - a hashref of values" ) + if @_ > 2; + + $self->throw_exception( "new_result expects a hashref" ) unless (ref $values eq 'HASH'); my ($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 => $self->result_source, # DO NOT REMOVE THIS, REQUIRED - ); + }); + + if ( + reftype($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, + )); + } - return $self->result_class->new(\%new); + $new; } # _merge_with_rscond @@ -2497,7 +2641,7 @@ sub _remove_alias { =item Arguments: none -=item Return Value: \[ $sql, @bind ] +=item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ] =back @@ -2510,27 +2654,24 @@ This is generally used as the RHS for a subquery. sub as_query { my $self = shift; - my $attrs = $self->_resolved_attrs_copy; + 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 + ); - return $sqlbind; + $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args}; + + $aq; } =head2 find_or_new =over 4 -=item Arguments: \%vals, \%attrs? +=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }? -=item Return Value: $rowobject +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> =back @@ -2538,7 +2679,7 @@ sub as_query { { 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. if none exists, instantiate a new result object and return it. The object will not be saved @@ -2575,9 +2716,9 @@ sub find_or_new { =over 4 -=item Arguments: \%vals +=item Arguments: \%col_data -=item Return Value: a L $object +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> =back @@ -2601,12 +2742,11 @@ 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 -L), will be inserted into their appropriate tables. +L), will be inserted into their appropriate tables. -Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. +Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>. Example of creating a new row. @@ -2644,28 +2784,29 @@ C resultset. Note Hashref. When subclassing ResultSet never attempt to override this method. Since it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a lot of the internals simply never call it, so your override will be -bypassed more often than not. Override either L -or L depending on how early in the -L process you need to intervene. +bypassed more often than not. Override either L +or L depending on how early in the +L process you need to intervene. See also warning pertaining to +L. =back =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 =over 4 -=item Arguments: \%vals, \%attrs? +=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }? -=item Return Value: $rowobject +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> =back @@ -2724,7 +2865,7 @@ database! year => 2005, }); - if( $cd->in_storage ) { + if( !$cd->in_storage ) { # do some stuff $cd->insert; } @@ -2745,16 +2886,16 @@ sub find_or_create { =over 4 -=item Arguments: \%col_values, { key => $unique_constraint }? +=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }? -=item Return Value: $row_object +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> =back $resultset->update_or_create({ col => $val, ... }); Like L, but if a row is found it is immediately updated via -C<< $found_row->update (\%col_values) >>. +C<< $found_row->update (\%col_data) >>. Takes an optional C attribute to search on a specific unique constraint. @@ -2795,20 +2936,6 @@ L and L instead. Don't forget to call L to save the newly created row to the database! - my $cd = $schema->resultset('CD')->update_or_new( - { - artist => 'Massive Attack', - title => 'Mezzanine', - year => 1998, - }, - { key => 'cd_artist_title' } - ); - - if( $cd->in_storage ) { - # do some stuff - $cd->insert; - } - =cut sub update_or_create { @@ -2829,16 +2956,16 @@ sub update_or_create { =over 4 -=item Arguments: \%col_values, { key => $unique_constraint }? +=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }? -=item Return Value: $rowobject +=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> =back $resultset->update_or_new({ col => $val, ... }); Like L but if a row is found it is immediately updated via -C<< $found_row->update (\%col_values) >>. +C<< $found_row->update (\%col_data) >>. For example: @@ -2894,7 +3021,7 @@ sub update_or_new { =item Arguments: none -=item Return Value: \@cache_objects | undef +=item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef =back @@ -2913,15 +3040,15 @@ sub get_cache { =over 4 -=item Arguments: \@cache_objects +=item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass> -=item Return Value: \@cache_objects +=item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> =back Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. Note that -if the cache is set the resultset will return the cached objects rather +if the cache is set, the resultset will return the cached objects rather than re-querying the database even if the cache attr is not set. The contents of the cache can also be populated by using the @@ -2992,9 +3119,9 @@ sub is_ordered { =over 4 -=item Arguments: $relationship_name +=item Arguments: $rel_name -=item Return Value: $resultset +=item Return Value: L<$resultset|/search> =back @@ -3007,8 +3134,10 @@ Returns a related resultset for the supplied relationship name. 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); @@ -3034,15 +3163,6 @@ sub related_resultset { #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 { @@ -3063,7 +3183,16 @@ sub related_resultset { 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; + } + $new; }; } @@ -3106,9 +3235,7 @@ source alias of the current result set: =cut sub current_source_alias { - my ($self) = @_; - - return ($self->{attrs} || {})->{alias} || 'me'; + return (shift->{attrs} || {})->{alias} || 'me'; } =head2 as_subselect_rs @@ -3117,7 +3244,7 @@ sub current_source_alias { =item Arguments: none -=item Return Value: $resultset +=item Return Value: L<$resultset|/search> =back @@ -3205,7 +3332,7 @@ sub _chain_relationship { # ->_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 $attrs->{seen_join}) || {} } }; @@ -3290,12 +3417,6 @@ sub _chain_relationship { return {%$attrs, from => $from, seen_join => $seen}; } -# too many times we have to do $attrs = { %{$self->_resolved_attrs} } -sub _resolved_attrs_copy { - my $self = shift; - return { %{$self->_resolved_attrs (@_)} }; -} - sub _resolved_attrs { my $self = shift; return $self->{_attrs} if $self->{_attrs}; @@ -3319,7 +3440,7 @@ sub _resolved_attrs { if (my $cols = delete $attrs->{columns}) { for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) { if (ref $c eq 'HASH') { - for my $as (keys %$c) { + for my $as (sort keys %$c) { push @sel, $c->{$as}; push @as, $as; } @@ -3341,14 +3462,10 @@ sub _resolved_attrs { if $attrs->{select}; # assume all unqualified selectors to apply to the current alias (legacy stuff) - for (@sel) { - $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_"; - } + $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel; - # disqualify all $alias.col as-bits (collapser mandated) - for (@as) { - $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_; - } + # disqualify all $alias.col as-bits (inflate-map mandated) + $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as; # de-duplicate the result (remove *identical* select/as pairs) # and also die on duplicate {as} pointing to different {select}s @@ -3425,25 +3542,24 @@ sub _resolved_attrs { 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); } } - $attrs->{collapse} ||= {}; - if ($attrs->{prefetch}) { + # generate selections based on the prefetch helper + my $prefetch; + $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} ) + if defined $attrs->{prefetch}; + + if ($prefetch) { $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}") if $attrs->{_dark_selector}; - my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{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 @@ -3466,22 +3582,64 @@ sub _resolved_attrs { } } - my @prefetch = - $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} ); - - # 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 ]; - } + my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map ); 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 ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) { + $attrs->{_related_results_construction} = 1; } + # run through the resulting joinstructure (starting from our current slot) + # and unset collapse if proven unnesessary + # + # also while we are at it find out if the current root source has + # been premultiplied by previous related_source chaining + # + # this allows to predict whether a root object with all other relation + # data set to NULL is in fact unique + if ($attrs->{collapse}) { + + if (ref $attrs->{from} eq 'ARRAY') { + + if (@{$attrs->{from}} == 1) { + # no joins - no collapse + $attrs->{collapse} = 0; + } + else { + # find where our table-spec starts + my @fromlist = @{$attrs->{from}}; + while (@fromlist) { + my $t = shift @fromlist; + + my $is_multi; + # me vs join from-spec distinction - a ref means non-root + if (ref $t eq 'ARRAY') { + $t = $t->[0]; + $is_multi ||= ! $t->{-is_single}; + } + last if ($t->{-alias} && $t->{-alias} eq $alias); + $attrs->{_main_source_premultiplied} ||= $is_multi; + } + + # no non-singles remaining, nor any premultiplication - nothing to collapse + if ( + ! $attrs->{_main_source_premultiplied} + and + ! List::Util::first { ! $_->[0]{-is_single} } @fromlist + ) { + $attrs->{collapse} = 0; + } + } + } + + else { + # if we can not analyze the from - err on the side of safety + $attrs->{_main_source_premultiplied} = 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 @@ -3607,7 +3765,7 @@ sub _merge_joinpref_attr { $seen_keys->{$import_key} = 1; # don't merge the same key twice } - return $orig; + return @$orig ? $orig : (); } { @@ -3703,7 +3861,8 @@ sub STORABLE_freeze { my $to_serialize = { %$self }; # A cursor in progress can't be serialized (and would make little sense anyway) - delete $to_serialize->{cursor}; + # the parser can be regenerated (and can't be serialized) + delete @{$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') { @@ -3740,6 +3899,10 @@ sub throw_exception { } } +1; + +__END__ + # XXX: FIXME: Attributes docs need clearing up =head1 ATTRIBUTES @@ -3749,6 +3912,10 @@ searching for data. They can be passed to any method which takes an C<\%attrs> argument. See L, L, L, L. +Default attributes can be set on the result class using +L. (Please read +the CAVEATS on that feature before using it!) + These are in no particular order: =head2 order_by @@ -3785,7 +3952,7 @@ syntax as outlined above. =over 4 -=item Value: \@columns +=item Value: \@columns | \%columns | $column =back @@ -3795,7 +3962,7 @@ case the key is the C value, and the value is used as the C from that, then auto-populates C from C and L. @@ -3814,10 +3981,10 @@ is the same as =back -Indicates additional columns to be selected from storage. Works the same -as L but adds columns to the selection. (You may also use the -C attribute, as in earlier versions of DBIC). For -example:- +Indicates additional columns to be selected from storage. Works the same as +L but adds columns to the selection. (You may also use the +C attribute, as in earlier versions of DBIC, but this is +deprecated). For example:- $schema->resultset('CD')->search(undef, { '+columns' => ['artist.name'], @@ -3887,14 +4054,6 @@ an explicit list. =back -=head2 +as - -=over 4 - -Indicates additional column names for those added via L. See L. - -=back - =head2 as =over 4 @@ -3937,6 +4096,14 @@ use C instead: You can create your own accessors if required - see L for details. +=head2 +as + +=over 4 + +Indicates additional column names for those added via L. See L. + +=back + =head2 join =over 4 @@ -4000,196 +4167,175 @@ similarly for a third time). For e.g. will return a set of all artists that have both a cd with title 'Down to Earth' and a cd with title 'Popular'. -If you want to fetch related objects from other tables as well, see C +If you want to fetch related objects from other tables as well, see L below. + NOTE: An internal join-chain pruner will discard certain joins while + constructing the actual SQL query, as long as the joins in question do not + affect the retrieved result. This for example includes 1:1 left joins + that are not part of the restriction specification (WHERE/HAVING) nor are + a part of the query selection. + For more help on using joins with search, see L. -=head2 prefetch +=head2 collapse =over 4 -=item Value: ($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: +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: - 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 has no need to go back to the database when we access the -C or C relationships, which saves us two SQL statements in this -case. - -Simple prefetches will be joined automatically, so there is no need -for a C attribute in the above search. - -L 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({}, { + '+columns' => [ qw/ tracks.title tracks.position / ], + join => 'tracks', + collapse => 1, + }); +While executing the following query: - 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 - ] - } - ); + SELECT me.*, tracks.title, tracks.position + FROM cd me + LEFT JOIN track tracks + ON tracks.cdid = me.cdid -This will produce SQL like the following: +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. 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. - 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 +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. -Now the C, C, C, C, -C, and C of the CD will all be available through the -relationship accessors without the need for additional queries to the -database. +If an L 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), DBIC will automatically +switch to "eager" mode and slurp the entire resultset before consturcting the +first object returned by L. -However, there is one caveat to be observed: it can be dangerous to -prefetch more than one L -relationship on a given level. e.g.: +Setting this attribute on a resultset that does not join any has_many +relations is a no-op. - my $rs = $schema->resultset('CD')->search( - undef, - { - prefetch => [ - 'tracks', # has_many - { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m) - ] - } - ); +For a more in-depth discussion, see L. -In fact, C will emit the following warning: +=head2 prefetch - Prefetching multiple has_many rels tracks and cd_to_producer at top - level will explode the number of row objects retrievable via ->next - or ->all. Use at your own risk. +=over 4 -The collapser currently can't identify duplicate tuples for multiple -L relationships and as a -result the second L -relation could contain redundant objects. +=item Value: ($rel_name | \@rel_names | \%rel_names) -=head3 Using L with L +=back -L implies a L with the equivalent argument, and is -properly merged with any existing L specification. So the -following: +This attribute is a shorthand for specifying a L spec, adding all +columns from the joined related sources as L and setting +L to a true value. For example, the following two queries are +equivalent: - my $rs = $schema->resultset('CD')->search( - {'record_label.name' => 'Music Product Ltd.'}, - { - join => {artist => 'record_label'}, - prefetch => 'artist', - } - ); + my $rs = $schema->resultset('Artist')->search({}, { + prefetch => { cds => ['genre', 'tracks' ] }, + }); -... will work, searching on the record label's name, but only -prefetching the C. +and -=head3 Using L with L / L / L / L + 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 + ), + ], + }); -L implies a L/L with the fields of the -prefetched relations. So given: +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 implies a L, 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', + } + ); - my $rs = $schema->resultset('CD')->search( - undef, - { - select => ['cd.title'], - as => ['cd_title'], - prefetch => 'artist', - } - ); +Which generates the following SQL: -The L becomes: C<'cd.title', 'artist.*'> and the L -becomes: C<'cd_title', 'artist.*'>. + 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 -=head3 CAVEATS +For a more in-depth discussion, see L. -Prefetch does a lot of deep magic. As such, it may not behave exactly -as you might expect. +=head2 alias =over 4 -=item * - -Prefetch uses the L to populate the prefetched relationships. This -may or may not be what you want. - -=item * +=item Value: $source_alias -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 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; +=back - my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } ); +Sets the source alias for the query. Normally, this defaults to C, but +nested search queries (sub-SELECTs) might need specific aliases set to +reference inner queries. For example: - my $prefetch_count = $artist_rs_prefetch->first->cds->count; + my $q = $rs + ->related_resultset('CDs') + ->related_resultset('Tracks') + ->search({ + 'track.id' => { -ident => 'none_search.id' }, + }) + ->as_query; - cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" ); + my $ids = $self->search({ + -not_exists => $q, + }, { + alias => 'none_search', + group_by => 'none_search.id', + })->get_column('id')->as_query; -that cmp_ok() may or may not pass depending on the datasets involved. This -behavior may or may not survive the 0.09 transition. + $self->search({ id => { -in => $ids } }) -=back +This attribute is directly tied to L. =head2 page @@ -4231,6 +4377,24 @@ rows per page if the page attribute or method is used. Specifies the (zero-based) row number for the first row to be returned, or the of the first row of the first page if paging is used. +=head2 software_limit + +=over 4 + +=item Value: (0 | 1) + +=back + +When combined with L and/or L the generated SQL will not +include any limit dialect stanzas. Instead the entire result will be selected +as if no limits were specified, and DBIC will perform the limit locally, by +artificially advancing and finishing the resulting L. + +This is the recommended way of performing resultset limiting when no sane RDBMS +implementation is available (e.g. +L using the +L hack) + =head2 group_by =over 4 @@ -4279,7 +4443,7 @@ attribute, this setting is ignored and an appropriate warning is issued. Adds to the WHERE clause. # only return rows WHERE deleted IS NULL for all searches - __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); ) + __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); Can be overridden by passing C<< { where => undef } >> as an attribute to a resultset. @@ -4310,13 +4474,193 @@ L. =over 4 -=item Value: ( 'update' | 'shared' ) +=item Value: ( 'update' | 'shared' | \$scalar ) =back Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT -... FOR SHARED. +... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the +query. -=cut +=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 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 has no need to go back to the database when we access the +C or C relationships, which saves us two SQL statements in this +case. + +Simple prefetches will be joined automatically, so there is no need +for a C attribute in the above search. + +The L 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, C, C, C, +C, and C 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 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 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 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 - consider declaring and using a L + +=back + +=head1 DBIC BIND VALUES + +Because DBIC may need more information to bind values than just the column name +and value itself, it uses a special format for both passing and receiving bind +values. Each bind value should be composed of an arrayref of +C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently: + +=over 4 + +=item dbd_attrs + +If present (in any form), this is what is being passed directly to bind_param. +Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes +a single numerical type, while DBD::Pg takes a hashref if bind options.) + +If this is specified, all other bind options described below are ignored. + +=item sqlt_datatype + +If present, this is used to infer the actual bind attribute by passing to +C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the +"data_type" from the L. + +Note that the data type is somewhat freeform (hence the sqlt_ prefix); +currently drivers are expected to "Do the Right Thing" when given a common +datatype name. (Not ideal, but that's what we got at this point.) + +=item sqlt_size + +Currently used to correctly allocate buffers for bind_param_inout(). +Defaults to "size" from the L, +or to a sensible value based on the "data_type". + +=item dbic_colname + +Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are +explicitly specified they are never overriden). Also used by some weird DBDs, +where the column name should be available at bind_param time (e.g. Oracle). + +=back + +For backwards compatibility and convenience, the following shortcuts are +supported: + + [ $name => $val ] === [ { dbic_colname => $name }, $val ] + [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ] + [ undef, $val ] === [ {}, $val ] + $val === [ {}, $val ] + +=head1 AUTHOR AND CONTRIBUTORS + +See L and L in DBIx::Class + +=head1 LICENSE + +You may distribute this code under the same terms as Perl itself. -1;