you want to check if a resultset has any results, you must use C<if $rs
!= 0>.
+=head1 CUSTOM ResultSet CLASSES THAT USE Moose
+
+If you want to make your custom ResultSet classes with L<Moose>, use a template
+similar to:
+
+ package MyApp::Schema::ResultSet::User;
+
+ use Moose;
+ use namespace::autoclean;
+ use MooseX::NonMoose;
+ extends 'DBIx::Class::ResultSet';
+
+ sub BUILDARGS { $_[2] }
+
+ ...your code...
+
+ __PACKAGE__->meta->make_immutable;
+
+ 1;
+
+The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
+clash with the regular ResultSet constructor. Alternatively, you can use:
+
+ __PACKAGE__->meta->make_immutable(inline_constructor => 0);
+
+The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
+signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
+
=head1 EXAMPLES
=head2 Chaining resultsets
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<DateTime>
objects, for more info see:
-L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
+L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
=cut
$attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
if exists $attrs->{include_columns};
- # columns are always placed first, however
+ # columns are always placed first, however
# Keep the X vs +X separation until _resolved_attrs time - this allows to
# delay the decision on whether to use a default select list ($rsrc->columns)
my $rsrc = $self->result_source;
+ my $constraint_name;
+ if (exists $attrs->{key}) {
+ $constraint_name = defined $attrs->{key}
+ ? $attrs->{key}
+ : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
+ ;
+ }
+
# Parse out the condition from input
my $call_cond;
+
if (ref $_[0] eq 'HASH') {
$call_cond = { %{$_[0]} };
}
else {
- my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
- my @c_cols = $rsrc->unique_constraint_columns($constraint);
+ # if only values are supplied we need to default to 'primary'
+ $constraint_name = 'primary' unless defined $constraint_name;
+
+ my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
$self->throw_exception(
- "No constraint columns, maybe a malformed '$constraint' constraint?"
+ "No constraint columns, maybe a malformed '$constraint_name' constraint?"
) unless @c_cols;
$self->throw_exception (
'find() expects either a column/value hashref, or a list of values '
- . "corresponding to the columns of the specified unique constraint '$constraint'"
+ . "corresponding to the columns of the specified unique constraint '$constraint_name'"
) unless @c_cols == @_;
$call_cond = {};
my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
my $final_cond;
- if (exists $attrs->{key}) {
+ if (defined $constraint_name) {
$final_cond = $self->_qualify_cond_columns (
$self->_build_unique_cond (
- $attrs->{key},
+ $constraint_name,
$call_cond,
),
# 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;
=over 4
-=item Arguments: $rel, $cond, \%attrs?
+=item Arguments: $rel, $cond?, \%attrs?
=item Return Value: $new_resultset (scalar context) || @row_objs (list context)
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'
- );
- }
+ $self->throw_exception(
+ 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
+ ) if $attrs->{collapse};
if ($where) {
if (defined $attrs->{where}) {
}
}
- 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 ];
+ $self->_construct_objects->[0];
}
sub next {
my ($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_objects}}) if @{ $self->{stashed_objects}||[] };
- 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_objects} = $self->_construct_objects
+ or return undef;
-sub _collapse_result {
- my ($self, $as_proto, $row) = @_;
-
- my @copy = @$row;
-
- # 'foo' => [ undef, 'foo' ]
- # 'foo.bar' => [ 'foo', 'bar' ]
- # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
-
- my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
-
- my %collapse = %{$self->{_attrs}{collapse}||{}};
-
- my @pri_index;
-
- # if we're doing collapsing (has_many prefetch) we need to grab records
- # until the PK changes, so fill @pri_index. if not, we leave it empty so
- # we know we don't have to bother.
-
- # the reason for not using the collapse stuff directly is because if you
- # had for e.g. two artists in a row with no cds, the collapse info for
- # both would be NULL (undef) so you'd lose the second artist
+ return shift @{$self->{stashed_objects}};
+}
- # store just the index so we can check the array positions from the row
- # without having to contruct the full hash
+# takes a single DBI-row of data and coinstructs as many objects
+# as the resultset attributes call for.
+# This can be a bit of an action at a distance - it takes as an argument
+# the *current* cursor-row (already taken off the $sth), but if
+# collapsing is requested it will keep advancing the cursor either
+# until the current row-object is assembled (the collapser was able to
+# order the result sensibly) OR until the cursor is exhausted (an
+# unordered collapsing resultset effectively triggers ->all)
+sub _construct_objects {
+ my ($self, $fetch_all) = @_;
- if (keys %collapse) {
- my %pri = map { ($_ => 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);
- }
- last unless keys %pri; # short circuit (Johnny Five Is Alive!)
- }
+ my $rsrc = $self->result_source;
+ my $attrs = $self->_resolved_attrs;
+ my $cursor = $self->cursor;
+
+ # this will be used as both initial raw-row collector AND as a RV of
+ # _construct_objects. Not regrowing the array twice matters a lot...
+ # a suprising amount actually
+ my $rows = (delete $self->{stashed_rows}) || [];
+ if ($fetch_all) {
+ # FIXME - we can do better, cursor->next/all (well diff. methods) should return a ref
+ $rows = [ @$rows, $cursor->all ];
}
+ elsif (!$attrs->{collapse}) {
+ push @$rows, do { my @r = $cursor->next; @r ? \@r : () }
+ unless @$rows;
+ }
+ else {
+ $attrs->{_ordered_for_collapse} ||= (!$attrs->{order_by}) ? undef : do {
+ my $st = $rsrc->schema->storage;
+ my @ord_cols = map
+ { $_->[0] }
+ ( $st->_extract_order_criteria($attrs->{order_by}) )
+ ;
- # no need to do an if, it'll be empty if @pri_index is empty anyway
-
- my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
-
- my @const_rows;
+ my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
- do { # no need to check anything at the front, we always want the first row
+ for (0 .. $#ord_cols) {
+ if (
+ ! $colinfos->{$ord_cols[$_]}
+ or
+ $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
+ ) {
+ splice @ord_cols, $_;
+ last;
+ }
+ }
- my %const;
+ # since all we check here are the start of the order_by belonging to the
+ # top level $rsrc, the order stability check will fail unless the whole
+ # thing is ordered as we need it
+ (@ord_cols and $rsrc->_identifying_column_set({ map
+ { $colinfos->{$_}{-colname} => $colinfos->{$_} }
+ @ord_cols
+ })) ? 1 : 0;
+ };
- foreach my $this_as (@construct_as) {
- $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
+ if ($attrs->{_ordered_for_collapse}) {
+ push @$rows, do { my @r = $cursor->next; @r ? \@r : () };
}
+ # instead of looping over ->next, use ->all in stealth mode
+ elsif (! $cursor->{done}) {
+ push @$rows, $cursor->all;
+ $cursor->{done} = 1;
+ $fetch_all = 1;
+ }
+ }
- push(@const_rows, \%const);
-
- } until ( # no pri_index => no collapse => drop straight out
- !@pri_index
- or
- do { # get another row, stash it, drop out if different PK
+ return undef unless @$rows;
- @copy = $self->cursor->next;
- $self->{stashed_row} = \@copy;
+ my $res_class = $self->result_class;
+ my $inflator = $res_class->can ('inflate_result')
+ or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
- # last thing in do block, counts as true if anything doesn't match
+ my $infmap = $attrs->{as};
- # check xor defined first for NULL vs. NOT NULL then if one is
- # defined the other must be so check string equality
+ if (!$attrs->{collapse} and $attrs->{_single_object_inflation}) {
+ # construct a much simpler array->hash folder for the one-table cases right here
- grep {
- (defined $pri_vals{$_} ^ defined $copy[$_])
- || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
- } @pri_index;
+ # FIXME SUBOPTIMAL this is a very very very hot spot
+ # while rather optimal we can *still* do much better, by
+ # building a smarter [Row|HRI]::inflate_result(), and
+ # switch to feeding it data via a much leaner interface
+ #
+ # crude unscientific benchmarking indicated the shortcut eval is not worth it for
+ # this particular resultset size
+ if (@$rows < 60) {
+ my @as_idx = 0..$#$infmap;
+ for my $r (@$rows) {
+ $r = $inflator->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } @as_idx } );
}
- );
-
- my $alias = $self->{attrs}{alias};
- my $info = [];
+ }
+ else {
+ eval sprintf (
+ '$_ = $inflator->($res_class, $rsrc, { %s }) for @$rows',
+ join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
+ );
+ }
+ }
+ else {
+ ($self->{_row_parser} ||= eval sprintf 'sub { %s }', $rsrc->_mk_row_parser({
+ inflate_map => $infmap,
+ selection => $attrs->{select},
+ collapse => $attrs->{collapse},
+ }) or die $@)->($rows, $fetch_all ? () : (
+ sub { my @r = $cursor->next or return; \@r },
+ ($self->{stashed_rows} = []),
+ )); # modify $rows in-place, shrinking/extending as necessary
- my %collapse_pos;
+ $_ = $inflator->($res_class, $rsrc, @$_) for @$rows;
- my @const_keys;
+ }
- 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};
- }
- }
+ # CDBI compat stuff
+ if ($attrs->{record_filter}) {
+ $_ = $attrs->{record_filter}->($_) for @$rows;
}
- return $info;
+ return $rows;
}
=head2 result_source
# extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
- # if we multi-prefetch we group_by primary keys only as this is what we would
+ # 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}} ) {
- $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
+ 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 '
+ . 'has_many prefetch before count()'
+ );
+ } ]
}
# Calculate subquery selector
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->{stashed_rows};
+ delete $self->{stashed_objects};
+
+ if (my $c = $self->get_cache) {
+ return @$c;
}
- $self->set_cache(\@obj) if $self->{attrs}{cache};
+ $self->cursor->reset;
+
+ my $objs = $self->_construct_objects('fetch_all') || [];
+
+ $self->set_cache($objs) if $self->{attrs}{cache};
- return @obj;
+ return @$objs;
}
=head2 reset
sub reset {
my ($self) = @_;
- delete $self->{_attrs} if exists $self->{_attrs};
+ delete $self->{_attrs};
+ delete $self->{stashed_rows};
+ delete $self->{stashed_objects};
+
$self->{all_cache_position} = 0;
$self->cursor->reset;
return $self;
sub _rs_update_delete {
my ($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
+ }
+
+ $needs_group_by_subq ||= exists $relation_classifications->{multiplying};
- my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
- my $needs_subq = $needs_group_by_subq || $self->_has_resolved_attr(qw/rows offset/);
+ # if no subquery - life is easy-ish
+ unless (
+ $needs_group_by_subq
+ or
+ keys %$relation_classifications # if any joins at all - need to wrap a subq
+ 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 $self->{cond};
- if ($needs_group_by_subq or $needs_subq) {
+ return $rsrc->storage->$op(
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $self->{cond} ? \[$sql, @bind] : (),
+ );
+ }
- # make a new $rs selecting only the PKs (that's all we really need)
- my $attrs = $self->_resolved_attrs_copy;
+ # 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,
+ )
+ );
+ 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 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);
- delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
- $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
+ if (@$idcols == 1) {
+ return $storage->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ { $idcols->[0] => { -in => $subrs->as_query } },
+ );
+ }
+ elsif ($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,
+ );
+ 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) {
- # make sure no group_by was supplied, or if there is one - make sure it matches
- # the columns compiled above perfectly. Anything else can not be sanely executed
- # on most databases so croak right then and there
+ $subq_group_by = $attrs->{columns};
- if (my $g = $attrs->{group_by}) {
+ # make sure if there is a supplied group_by it matches the columns compiled above
+ # perfectly. Anything else can not be sanely executed on most databases so croak
+ # right then and there
+ if ($existing_group_by) {
my @current_group_by = map
{ $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
- @$g
+ @$existing_group_by
;
if (
join ("\x00", sort @current_group_by)
ne
- join ("\x00", sort @{$attrs->{columns}} )
+ join ("\x00", sort @$subq_group_by )
) {
$self->throw_exception (
"You have just attempted a $op operation on a resultset which does group_by"
);
}
}
- else {
- $attrs->{group_by} = $attrs->{columns};
- }
}
- my $subrs = (ref $self)->new($rsrc, $attrs);
- return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
- }
- else {
- # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
- # a condition containing 'me' or other table prefixes will not work
- # at all. What this code tries to do (badly) is to generate a condition
- # with the qualifiers removed, by exploiting the quote mechanism of sqla
- #
- # this is atrocious and should be replaced by normal sqla introspection
- # one sunny day
- my ($sql, @bind) = do {
- my $sqla = $rsrc->storage->sql_maker;
- local $sqla->{_dequalify_idents} = 1;
- $sqla->_recurse_where($self->{cond});
- } if $self->{cond};
+ my $guard = $storage->txn_scope_guard;
- return $rsrc->storage->$op(
+ my @op_condition;
+ for my $row ($subrs->search({}, { group_by => $subq_group_by })->cursor->all) {
+ push @op_condition, { map
+ { $idcols->[$_] => $row->[$_] }
+ (0 .. $#$idcols)
+ };
+ }
+
+ my $res = $storage->$op (
$rsrc,
$op eq 'update' ? $values : (),
- $self->{cond} ? \[$sql, @bind] : (),
+ \@op_condition,
);
+
+ $guard->commit;
+
+ return $res;
}
}
resultset (this includes the contents of the L<resultset cache|/set_cache>
if any). See L</update_all> if you need to execute any on-update
triggers or cascades defined either by you or a
-L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
+L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
The return value is a pass through of what the underlying
storage backend returned, and may vary. See L<DBI/execute> for the most
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<DateTime> objects, for more info see:
-L<DBIx::Class::Manual::Cookbook/Formatting_DateTime_objects_in_queries>.
+L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
=cut
derived from this resultset (this includes the contents of the
L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
execute any on-delete triggers or cascades defined either by you or a
-L<result component|DBIx::Class::Manual::Component/WHAT_IS_A_COMPONENT>.
+L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
The return value is a pass through of what the underlying storage backend
returned, and may vary. See L<DBI/execute> for the most common case.
push(@created, $self->create($item));
}
return wantarray ? @created : \@created;
- }
+ }
else {
my $first = $data->[0];
=cut
-# make a wizard good for both a scalar and a hashref
-my $mk_lazy_count_wizard = sub {
- require Variable::Magic;
-
- my $stash = { total_rs => shift };
- my $slot = shift; # only used by the hashref magic
-
- my $magic = Variable::Magic::wizard (
- data => sub { $stash },
-
- (!$slot)
- ? (
- # the scalar magic
- get => sub {
- # set value lazily, and dispell for good
- ${$_[0]} = $_[1]{total_rs}->count;
- Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
- return 1;
- },
- set => sub {
- # an explicit set implies dispell as well
- # the unless() is to work around "fun and giggles" below
- Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
- unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
- return 1;
- },
- )
- : (
- # the uvar magic
- fetch => sub {
- if ($_[2] eq $slot and !$_[1]{inactive}) {
- my $cnt = $_[1]{total_rs}->count;
- $_[0]->{$slot} = $cnt;
-
- # attempting to dispell in a fetch handle (works in store), seems
- # to invariable segfault on 5.10, 5.12, 5.13 :(
- # so use an inactivator instead
- #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
- $_[1]{inactive}++;
- }
- return 1;
- },
- store => sub {
- if (! $_[1]{inactive} and $_[2] eq $slot) {
- #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
- $_[1]{inactive}++
- unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
- }
- return 1;
- },
- ),
- );
-
- $stash->{magic_selfref} = $magic;
- weaken ($stash->{magic_selfref}); # this fails on 5.8.1
-
- return $magic;
-};
-
-# the tie class for 5.8.1
-{
- package # hide from pause
- DBIx::Class::__DBIC_LAZY_RS_COUNT__;
- use base qw/Tie::Hash/;
-
- sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
- sub NEXTKEY { each %{$_[0]{data}} }
- sub EXISTS { exists $_[0]{data}{$_[1]} }
- sub DELETE { delete $_[0]{data}{$_[1]} }
- sub CLEAR { %{$_[0]{data}} = () }
- sub SCALAR { scalar %{$_[0]{data}} }
-
- sub TIEHASH {
- $_[1]{data} = {%{$_[1]{selfref}}};
- %{$_[1]{selfref}} = ();
- Scalar::Util::weaken ($_[1]{selfref});
- return bless ($_[1], $_[0]);
- };
-
- sub FETCH {
- if ($_[1] eq $_[0]{slot}) {
- my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
- untie %{$_[0]{selfref}};
- %{$_[0]{selfref}} = %{$_[0]{data}};
- return $cnt;
- }
- else {
- $_[0]{data}{$_[1]};
- }
- }
-
- sub STORE {
- $_[0]{data}{$_[1]} = $_[2];
- if ($_[1] eq $_[0]{slot}) {
- untie %{$_[0]{selfref}};
- %{$_[0]{selfref}} = %{$_[0]{data}};
- }
- $_[2];
- }
-}
-
sub pager {
my ($self) = @_;
# with a subselect) to get the real total count
my $count_attrs = { %$attrs };
delete $count_attrs->{$_} for qw/rows offset page pager/;
- my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
-
-### the following may seem awkward and dirty, but it's a thought-experiment
-### necessary for future development of DBIx::DS. Do *NOT* change this code
-### before talking to ribasushi/mst
+ my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
- require Data::Page;
- my $pager = Data::Page->new(
- 0, #start with an empty set
+ require DBIx::Class::ResultSet::Pager;
+ return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
+ sub { $total_rs->count }, #lazy-get the total
$attrs->{rows},
$self->{attrs}{page},
);
-
- my $data_slot = 'total_entries';
-
- # Since we are interested in a cached value (once it's set - it's set), every
- # technique will detach from the magic-host once the time comes to fire the
- # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
-
- if ($] < 5.008003) {
- # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
- # to weakref the magic container :(
- # tested on 5.8.1
- tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
- { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
- );
- }
- elsif ($] < 5.010) {
- # We can use magic on the hash value slot. It's interesting that the magic is
- # attached to the hash-slot, and does *not* stop working once I do the dummy
- # assignments after the cast()
- # tested on 5.8.3 and 5.8.9
- my $magic = $mk_lazy_count_wizard->($total_rs);
- Variable::Magic::cast ( $pager->{$data_slot}, $magic );
-
- # this is for fun and giggles
- $pager->{$data_slot} = -1;
- $pager->{$data_slot} = 0;
-
- # this does not work for scalars, but works with
- # uvar magic below
- #my %vals = %$pager;
- #%$pager = ();
- #%{$pager} = %vals;
- }
- else {
- # And the uvar magic
- # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
- # however see the wizard maker for more notes
- my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
- Variable::Magic::cast ( %$pager, $magic );
-
- # still works
- $pager->{$data_slot} = -1;
- $pager->{$data_slot} = 0;
-
- # this now works
- my %vals = %$pager;
- %$pager = ();
- %{$pager} = %vals;
- }
-
- return $self->{pager} = $pager;
}
=head2 page
See also L</find> and L</update_or_create>. For information on how to declare
unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+If you need to know if an existing row was found or a new one created use
+L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
+to call L<DBIx::Class::Row/insert> to save the newly created row to the
+database!
+
+ my $cd = $schema->resultset('CD')->find_or_new({
+ cdid => 5,
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ year => 2005,
+ });
+
+ if( $cd->in_storage ) {
+ # do some stuff
+ $cd->insert;
+ }
+
=cut
sub find_or_create {
See also L</find> and L</find_or_create>. For information on how to declare
unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+If you need to know if an existing row was updated or a new one created use
+L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
+to call L<DBIx::Class::Row/insert> 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 {
In normal usage, the value of such columns should NOT be included at
all in the call to C<update_or_new>, even when set to C<undef>.
-See also L</find>, L</find_or_create> and L</find_or_new>.
+See also L</find>, L</find_or_create> and L</find_or_new>.
=cut
if (my $cache = $self->get_cache) {
if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
- $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
+ $new_cache = [ map { @{$_->related_resultset($rel)->get_cache||[]} }
@$cache ];
}
}
my $me = $self->current_source_alias;
- return $self->search(
+ return $self->search({
"$me.modified" => $user->id,
- );
+ });
}
=cut
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
}
}
- $attrs->{collapse} ||= {};
- if ($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
}
}
- my @prefetch =
- $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
+ my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
# we need to somehow mark which columns came from prefetch
if (@prefetch) {
push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
+ }
+
+ $attrs->{_single_object_inflation} = ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}};
+
+ # run through the resulting joinstructure (starting from our current slot)
+ # and unset collapse if proven unnesessary
+ if ($attrs->{collapse} && ref $attrs->{from} eq 'ARRAY') {
- push( @{$attrs->{order_by}}, @$prefetch_ordering );
- $attrs->{_collapse_order_by} = \@$prefetch_ordering;
+ if (@{$attrs->{from}} > 1) {
+
+ # find where our table-spec starts and consider only things after us
+ my @fromlist = @{$attrs->{from}};
+ while (@fromlist) {
+ my $t = shift @fromlist;
+ $t = $t->[0] if ref $t eq 'ARRAY'; #me vs join from-spec mismatch
+ last if ($t->{-alias} && $t->{-alias} eq $alias);
+ }
+
+ for (@fromlist) {
+ $attrs->{collapse} = ! $_->[0]{-is_single}
+ and last;
+ }
+ }
+ else {
+ # no joins - no collapse
+ $attrs->{collapse} = 0;
+ }
}
+ if (! $attrs->{order_by} and $attrs->{collapse}) {
+ # default order for collapsing unless the user asked for something
+ $attrs->{order_by} = [ map { "$alias.$_" } $source->primary_columns ];
+ $attrs->{_ordered_for_collapse} = 1;
+ }
# 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
$position++;
}
my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
+ $import_key = '' if not defined $import_key;
if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
push( @{$orig}, $import_element );
# A cursor in progress can't be serialized (and would make little sense anyway)
delete $to_serialize->{cursor};
+ # the parser can be regenerated
+ delete $to_serialize->{_row_parser};
+
+ # nor is it sensical to store a not-yet-fired-count pager
+ if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
+ delete $to_serialize->{pager};
+ }
+
Storable::nfreeze($to_serialize);
}
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</rows> and/or L</offset> 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</cursor>.
+
+This is the recommended way of performing resultset limiting when no sane RDBMS
+implementation is available (e.g.
+L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
+L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
+
=head2 group_by
=over 4
Can be overridden by passing C<< { where => undef } >> as an attribute
to a resultset.
+For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
+
=back
=head2 cache
projects / dbsrgits/DBIx-Class.git / blobdiff