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
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</new_result> 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 C<new_result> directly,
+so overloading this method with the idea of intercepting new result object
+creation B<will not work>. See also warning pertaining to L</create>.
+
+=back
=cut
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)
=over 4
-=item Arguments: $rel, $cond, \%attrs?
+=item Arguments: $rel, $cond?, \%attrs?
=item Return Value: $new_resultset (scalar context) || @row_objs (list context)
# extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
delete @{$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) ]
+ $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
+ $rsrc->_identifying_column_set || $self->throw_exception(
+ 'Unable to construct a unique group_by criteria properly collapsing the '
+ . 'has_many prefetch before count()'
+ );
+ } ]
}
# Calculate subquery selector
sub _rs_update_delete {
my ($self, $op, $values) = @_;
+ my $cond = $self->{cond};
my $rsrc = $self->result_source;
+ my $storage = $rsrc->schema->storage;
- 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/);
+ my $attrs = { %{$self->_resolved_attrs} };
- if ($needs_group_by_subq or $needs_subq) {
+ my $existing_group_by = delete $attrs->{group_by};
+ my $needs_subq = defined $existing_group_by;
- # make a new $rs selecting only the PKs (that's all we really need)
- my $attrs = $self->_resolved_attrs_copy;
+ # simplify the joinmap and maybe decide if a subquery is necessary
+ my $relation_classifications = {};
+ if (ref($attrs->{from}) eq 'ARRAY') {
+ # if we already know we need a subq, no point of classifying relations
+ if (!$needs_subq and @{$attrs->{from}} > 1) {
+ $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs);
- delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
- $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
+ $relation_classifications = $storage->_resolve_aliastypes_from_select_args (
+ [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
+ $attrs->{select},
+ $cond,
+ $attrs
+ );
+ }
+ }
+ else {
+ $needs_subq ||= 1; # if {from} is unparseable assume the worst
+ }
+
+ # do we need anything like a subquery?
+ if (
+ ! $needs_subq
+ and
+ ! keys %{ $relation_classifications->{restricting} || {} }
+ and
+ ! $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. Tell SQLMaker to dequalify idents via a gross hack.
+ my $cond = do {
+ my $sqla = $rsrc->storage->sql_maker;
+ local $sqla->{_dequalify_idents} = 1;
+ \[ $sqla->_recurse_where($self->{cond}) ];
+ };
+ return $rsrc->storage->$op(
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $cond,
+ );
+ }
+
+ # 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,
+ )
+ );
+
+ # 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 => $subrs->as_query } },
+ );
+ }
+ elsif ($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),
+ $sql,
+ );
- if ($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
+ return $storage->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ \[$sql, @bind],
+ );
+ }
+ else {
- if (my $g = $attrs->{group_by}) {
+ # 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
+ if (
+ $existing_group_by
+ or
+ keys %{ $relation_classifications->{multiplying} || {} }
+ ) {
+ # make sure if there is a supplied group_by it matches the columns compiled above
+ # perfectly. Anything else can not be sanely executed on most databases so croak
+ # right then and there
+ if ($existing_group_by) {
my @current_group_by = map
{ $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
- @$g
+ @$existing_group_by
;
if (
);
}
}
- else {
- $attrs->{group_by} = $attrs->{columns};
- }
+
+ $subrs = $subrs->search({}, { 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->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 = $data->[0];
sub new_result {
my ($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);
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</new>), will be inserted into their appropriate tables.
lot of the internals simply never call it, so your override will be
bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
or L<insert|DBIx::Class::Row/insert> depending on how early in the
-L</create> process you need to intervene.
+L</create> process you need to intervene. See also warning pertaining to
+L</new>.
=back
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!
+
=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
my $me = $self->current_source_alias;
- return $self->search(
+ return $self->search({
"$me.modified" => $user->id,
- );
+ });
}
=cut
$attrs->{_collapse_order_by} = \@$prefetch_ordering;
}
-
# if both page and offset are specified, produce a combined offset
# even though it doesn't make much sense, this is what pre 081xx has
# been doing
$position++;
}
my ($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 );
If you want to fetch related objects from other tables as well, see C<prefetch>
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<DBIx::Class::Manual::Joining>.
=head2 prefetch
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
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.
+For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
+
=back
=head2 cache
=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
projects / dbsrgits/DBIx-Class.git / blobdiff