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
=head2 search_literal
+B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
+should only be used in that context. C<search_literal> is a convenience
+method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
+want to ensure columns are bound correctly, use L</search>.
+
+See L<DBIx::Class::Manual::Cookbook/Searching> and
+L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
+require C<search_literal>.
+
=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)
Pass a literal chunk of SQL to be added to the conditional part of the
resultset query.
-CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
-only be used in that context. C<search_literal> is a convenience method.
-It is equivalent to calling $schema->search(\[]), but if you want to ensure
-columns are bound correctly, use C<search>.
-
Example of how to use C<search> instead of C<search_literal>
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<DBIx::Class::Manual::Cookbook/Searching> and
-L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
-require C<search_literal>.
-
=cut
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
=head2 count_literal
+B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
+should only be used in that context. See L</search_literal> for further info.
+
=over 4
-=item Arguments: $sql_fragment, @bind_values
+=item Arguments: $sql_fragment, @standalone_bind_values
=item Return Value: $count
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};
+ my $existing_group_by = delete $attrs->{group_by};
+ my $needs_subq = defined $existing_group_by;
+
+ # simplify the joinmap and maybe decide if a subquery is necessary
+ my $relation_classifications = {};
- # 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, $attrs);
+ # if we already know we need a subq, no point of classifying relations
+ if (!$needs_subq and @{$attrs->{from}} > 1) {
+ $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs);
- $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
+ $relation_classifications = $storage->_resolve_aliastypes_from_select_args (
+ [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
+ $attrs->{select},
+ $cond,
+ $attrs
+ );
+ }
}
else {
- $needs_group_by_subq ||= 1; # if {from} is unparseable assume the worst
+ $needs_subq ||= 1; # if {from} is unparseable assume the worst
}
- $needs_group_by_subq ||= exists $relation_classifications->{multiplying};
-
- # 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
+ # do we need anything like a subquery?
+ if (
+ ! $needs_subq
+ and
+ ! keys %{ $relation_classifications->{restricting} || {} }
+ and
+ ! $self->_has_resolved_attr(qw/rows offset/) # limits call for a subq
) {
# Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
# a condition containing 'me' or other table prefixes will not work
- # at all. What this code tries to do (badly) is to generate a condition
- # with the qualifiers removed, by exploiting the quote mechanism of sqla
- #
- # this is atrocious and should be replaced by normal sqla introspection
- # one sunny day
- my ($sql, @bind) = do {
+ # 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});
- } if $self->{cond};
-
+ \[ $sqla->_recurse_where($self->{cond}) ];
+ };
return $rsrc->storage->$op(
$rsrc,
$op eq 'update' ? $values : (),
- $self->{cond} ? \[$sql, @bind] : (),
+ $cond,
);
}
$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 _collapse_order_by select _prefetch_selector_range as/;
);
}
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};
-
+ if (
+ $existing_group_by
+ or
+ keys %{ $relation_classifications->{multiplying} || {} }
+ ) {
# make sure if there is a supplied group_by it matches the columns compiled above
# perfectly. Anything else can not be sanely executed on most databases so croak
# right then and there
if (
join ("\x00", sort @current_group_by)
ne
- join ("\x00", sort @$subq_group_by )
+ join ("\x00", sort @{$attrs->{columns}} )
) {
$self->throw_exception (
"You have just attempted a $op operation on a resultset which does group_by"
);
}
}
+
+ $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
}
my $guard = $storage->txn_scope_guard;
my @op_condition;
- for my $row ($subrs->search({}, { group_by => $subq_group_by })->cursor->all) {
+ for my $row ($subrs->cursor->all) {
push @op_condition, { map
{ $idcols->[$_] => $row->[$_] }
(0 .. $#$idcols)
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);
=item Arguments: none
-=item Return Value: \[ $sql, @bind ]
+=item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
=back
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
year => 2005,
});
- if( $cd->in_storage ) {
+ if( !$cd->in_storage ) {
# do some stuff
$cd->insert;
}
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 {
$attrs->{_collapse_order_by} = \@$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
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
=back
+=head2 alias
+
+=over 4
+
+=item Value: $source_alias
+
+=back
+
+Sets the source alias for the query. Normally, this defaults to C<me>, but
+nested search queries (sub-SELECTs) might need specific aliases set to
+reference inner queries. For example:
+
+ my $q = $rs
+ ->related_resultset('CDs')
+ ->related_resultset('Tracks')
+ ->search({
+ 'track.id' => { -ident => 'none_search.id' },
+ })
+ ->as_query;
+
+ my $ids = $self->search({
+ -not_exists => $q,
+ }, {
+ alias => 'none_search',
+ group_by => 'none_search.id',
+ })->get_column('id')->as_query;
+
+ $self->search({ id => { -in => $ids } })
+
+This attribute is directly tied to L</current_source_alias>.
+
=head2 page
=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.
=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.
+
+=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<add_columns column info|DBIx::Class::ResultSource/add_columns>.
+
+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<add_columns column info|DBIx::Class::ResultSource/add_columns>,
+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 ]
+
+=head1 AUTHOR AND CONTRIBUTORS
+
+See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
=cut
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