use strict;
use warnings;
use overload
- '0+' => \&count,
- 'bool' => sub { 1; },
+ '0+' => "count",
+ 'bool' => "_bool",
fallback => 1;
use Carp::Clan qw/^DBIx::Class/;
use Data::Page;
use Storable;
use DBIx::Class::ResultSetColumn;
use DBIx::Class::ResultSourceHandle;
+use List::Util ();
+use Scalar::Util ();
use base qw/DBIx::Class/;
-__PACKAGE__->mk_group_accessors('simple' => qw/result_class _source_handle/);
+__PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
=head1 NAME
=head1 SYNOPSIS
- my $rs = $schema->resultset('User')->search(registered => 1);
- my @rows = $schema->resultset('CD')->search(year => 2005);
+ my $rs = $schema->resultset('User')->search({ registered => 1 });
+ my @rows = $schema->resultset('CD')->search({ year => 2005 })->all();
=head1 DESCRIPTION
__PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
1;
+=head1 OVERLOADING
+
+If a resultset is used in a numeric context it returns the L</count>.
+However, if it is used in a booleand context it is always true. So if
+you want to check if a resultset has any results use C<if $rs != 0>.
+C<if $rs> will always be true.
+
=head1 METHODS
=head2 new
if ($attrs->{page}) {
$attrs->{rows} ||= 10;
- $attrs->{offset} ||= ($attrs->{rows} * ($attrs->{page} - 1));
}
$attrs->{alias} ||= 'me';
+ # Creation of {} and bless separated to mitigate RH perl bug
+ # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
my $self = {
_source_handle => $source,
- result_class => $attrs->{result_class} || $source->resolve->result_class,
cond => $attrs->{where},
count => undef,
pager => undef,
bless $self, $class;
+ $self->result_class(
+ $attrs->{result_class} || $source->resolve->result_class
+ );
+
return $self;
}
L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
documentation for the first argument, see L<SQL::Abstract>.
+For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
+
=cut
sub search {
sub search_rs {
my $self = shift;
- my $rows;
-
- unless (@_) { # no search, effectively just a clone
- $rows = $self->get_cache;
- }
-
my $attrs = {};
$attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
my $our_attrs = { %{$self->{attrs}} };
my $having = delete $our_attrs->{having};
my $where = delete $our_attrs->{where};
+ my $rows;
+
+ my %safe = (alias => 1, cache => 1);
+
+ unless (
+ (@_ && defined($_[0])) # @_ == () or (undef)
+ ||
+ (keys %$attrs # empty attrs or only 'safe' attrs
+ && List::Util::first { !$safe{$_} } keys %$attrs)
+ ) {
+ # no search, effectively just a clone
+ $rows = $self->get_cache;
+ }
+
my $new_attrs = { %{$our_attrs}, %{$attrs} };
# merge new attrs into inherited
- foreach my $key (qw/join prefetch/) {
+ foreach my $key (qw/join prefetch +select +as/) {
next unless exists $attrs->{$key};
$new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
}
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. There are known problems using C<search_literal>
+in chained queries; it can result in bind values in the wrong order. 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 {
=item Arguments: @values | \%cols, \%attrs?
-=item Return Value: $row_object
+=item Return Value: $row_object | undef
=back
If the C<key> is specified as C<primary>, it searches only on the primary key.
If no C<key> is specified, it searches on all unique constraints defined on the
-source, including the primary key.
+source for which column data is provided, including the primary key.
If your table does not have a primary key, you B<must> provide a value for the
C<key> attribute matching one of the unique constraints on the source.
+In addition to C<key>, L</find> recognizes and applies standard
+L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
+
+Note: If your query does not return only one row, a warning is generated:
+
+ Query returned more than one row
+
See also L</find_or_create> and L</update_or_create>. For information on how to
declare unique constraints, see
L<DBIx::Class::ResultSource/add_unique_constraint>.
@{$input_query}{@keys} = values %related;
}
- my @unique_queries = $self->_unique_queries($input_query, $attrs);
# Build the final query: Default to the disjunction of the unique queries,
# but allow the input query in case the ResultSet defines the query or the
# user is abusing find
my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
- my $query = @unique_queries
- ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
- : $self->_add_alias($input_query, $alias);
+ my $query;
+ if (exists $attrs->{key}) {
+ my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
+ my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
+ $query = $self->_add_alias($unique_query, $alias);
+ }
+ else {
+ my @unique_queries = $self->_unique_queries($input_query, $attrs);
+ $query = @unique_queries
+ ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
+ : $self->_add_alias($input_query, $alias);
+ }
# Run the query
if (keys %$attrs) {
my $rs = $self->search($query, $attrs);
- return keys %{$rs->_resolved_attrs->{collapse}} ? $rs->next : $rs->single;
+ if (keys %{$rs->_resolved_attrs->{collapse}}) {
+ my $row = $rs->next;
+ carp "Query returned more than one row" if $rs->next;
+ return $row;
+ }
+ else {
+ return $rs->single;
+ }
}
else {
- return keys %{$self->_resolved_attrs->{collapse}}
- ? $self->search($query)->next
- : $self->single($query);
+ if (keys %{$self->_resolved_attrs->{collapse}}) {
+ my $rs = $self->search($query);
+ my $row = $rs->next;
+ carp "Query returned more than one row" if $rs->next;
+ return $row;
+ }
+ else {
+ return $self->single($query);
+ }
}
}
return shift->related_resultset(shift)->search(@_);
}
+=head2 search_related_rs
+
+This method works exactly the same as search_related, except that
+it guarantees a restultset, even in list context.
+
+=cut
+
+sub search_related_rs {
+ return shift->related_resultset(shift)->search_rs(@_);
+}
+
=head2 cursor
=over 4
my $cd = $schema->resultset('CD')->single({ year => 2001 });
Inflates the first result without creating a cursor if the resultset has
-any records in it; if not returns nothing. Used by L</find> as an optimisation.
+any records in it; if not returns nothing. Used by L</find> as a lean version of
+L</search>.
+
+While this method can take an optional search condition (just like L</search>)
+being a fast-code-path it does not recognize search attributes. If you need to
+add extra joins or similar, call L</search> and then chain-call L</single> on the
+L<DBIx::Class::ResultSet> returned.
+
+=over
+
+=item B<Note>
-Can optionally take an additional condition *only* - this is a fast-code-path
-method; if you need to add extra joins or similar call ->search and then
-->single without a condition on the $rs returned from that.
+As of 0.08100, this method enforces the assumption that the preceeding
+query returns only one row. If more than one row is returned, you will receive
+a warning:
+
+ Query returned more than one row
+
+In this case, you should be using L</first> or L</find> instead, or if you really
+know what you are doing, use the L</rows> attribute to explicitly limit the size
+of the resultset.
+
+=back
=cut
$cd_rs = $rs->search_like({ title => '%blue%'});
Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
-that this is simply a convenience method. You most likely want to use
-L</search> with specific operators.
+that this is simply a convenience method retained for ex Class::DBI users.
+You most likely want to use L</search> with specific operators.
For more information, see L<DBIx::Class::Manual::Cookbook>.
my @const_keys;
- use Data::Dumper;
-
foreach my $const (@const_rows) {
scalar @const_keys or do {
@const_keys = sort { length($a) <=> length($b) } keys %$const;
=cut
+sub result_class {
+ my ($self, $result_class) = @_;
+ if ($result_class) {
+ $self->ensure_class_loaded($result_class);
+ $self->_result_class($result_class);
+ }
+ $self->_result_class;
+}
=head2 count
with to find the number of elements. If passed arguments, does a search
on the resultset and counts the results of that.
-Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
+Note: When using C<count> with C<group_by>, L<DBIx::Class> emulates C<GROUP BY>
using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
not support C<DISTINCT> with multiple columns. If you are using such a
database, you should only use columns from the main table in your C<group_by>
my $count = $self->_count;
return 0 unless $count;
- $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
+ # need to take offset from resolved attrs
+
+ $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
$count = $self->{attrs}{rows} if
$self->{attrs}{rows} and $self->{attrs}{rows} < $count;
+ $count = 0 if ($count < 0);
return $count;
}
# offset, order by and page are not needed to count. record_filter is cdbi
delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
- my $tmp_rs = (ref $self)->new($self->_source_handle, $attrs);
+ my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
my ($count) = $tmp_rs->cursor->next;
return $count;
}
+sub _bool {
+ return 1;
+}
+
=head2 count_literal
=over 4
will not run DBIC cascade triggers. See L</delete_all> if you need triggers
to run. See also L<DBIx::Class::Row/delete>.
+delete may not generate correct SQL for a query with joins or a resultset
+chained from a related resultset. In this case it will generate a warning:-
+
+ WARNING! Currently $rs->delete() does not generate proper SQL on
+ joined resultsets, and may delete rows well outside of the contents
+ of $rs. Use at your own risk
+
+In these cases you may find that delete_all is more appropriate, or you
+need to respecify your query in a way that can be expressed without a join.
+
=cut
sub delete {
my ($self) = @_;
-
+ $self->throw_exception("Delete should not be passed any arguments")
+ if $_[1];
+ carp( 'WARNING! Currently $rs->delete() does not generate proper SQL'
+ . ' on joined resultsets, and may delete rows well outside of the'
+ . ' contents of $rs. Use at your own risk' )
+ if ( $self->{attrs}{seen_join} );
my $cond = $self->_cond_for_update_delete;
$self->result_source->storage->delete($self->result_source, $cond);
=back
-Pass an arrayref of hashrefs. 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.
+For the arrayref of hashrefs style each hashref should be a structure suitable
+forsubmitting to a $resultset->create(...) method.
In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
-to insert the data, as this is a faster method.
+to insert the data, as this is a faster method.
Otherwise, each set of data is inserted into the database using
L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
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:
+
+ $Arstist_rs->populate([
+ [qw/artistid name/],
+ [100, 'A Formally Unknown Singer'],
+ [101, 'A singer that jumped the shark two albums ago'],
+ [102, 'An actually cool singer.'],
+ ]);
+
+Please note an important effect on your data when choosing between void and
+wantarray context. Since void context goes straight to C<insert_bulk> in
+L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
+c<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
+create primary keys for you, you will find that your PKs are empty. In this
+case you will have to use the wantarray context in order to create those
+values.
+
=cut
sub populate {
- my ($self, $data) = @_;
+ my $self = shift @_;
+ my $data = ref $_[0][0] eq 'HASH'
+ ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) :
+ $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs');
if(defined wantarray) {
my @created;
}
## do bulk insert on current row
- my @values = map {
- [ map {
- defined $_ ? $_ : $self->throw_exception("Undefined value for column!")
- } @$_{@names} ]
- } @$data;
+ my @values = map { [ @$_{@names} ] } @$data;
$self->result_source->storage->insert_bulk(
$self->result_source,
}
}
+=head2 _normalize_populate_args ($args)
+
+Private method used by L</populate> to normalize its incoming arguments. Factored
+out in case you want to subclass and accept new argument structures to the
+L</populate> method.
+
+=cut
+
+sub _normalize_populate_args {
+ my ($self, $data) = @_;
+ my @names = @{shift(@$data)};
+ my @results_to_create;
+ foreach my $datum (@$data) {
+ my %result_to_create;
+ foreach my $index (0..$#names) {
+ $result_to_create{$names[$index]} = $$datum[$index];
+ }
+ push @results_to_create, \%result_to_create;
+ }
+ return \@results_to_create;
+}
+
=head2 pager
=over 4
sub page {
my ($self, $page) = @_;
- return (ref $self)->new($self->_source_handle, { %{$self->{attrs}}, page => $page });
+ return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
}
=head2 new_result
=item Arguments: \%vals
-=item Return Value: $object
+=item Return Value: $rowobject
=back
-Creates an object in the resultset's result class and returns it.
+Creates a new row object in the resultset's result class and returns
+it. The row is not inserted into the database at this point, call
+L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
+will tell you whether the row object has been inserted or not.
+
+Passes the hashref of input on to L<DBIx::Class::Row/new>.
=cut
my ($self, $values) = @_;
$self->throw_exception( "new_result needs a hash" )
unless (ref $values eq 'HASH');
- $self->throw_exception(
- "Can't abstract implicit construct, condition not a hash"
- ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
+ my %new;
my $alias = $self->{attrs}{alias};
- my $collapsed_cond = $self->{cond} ? $self->_collapse_cond($self->{cond}) : {};
- my %new = (
+
+ if (
+ defined $self->{cond}
+ && $self->{cond} eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION
+ ) {
+ %new = %{$self->{attrs}{related_objects}};
+ } else {
+ $self->throw_exception(
+ "Can't abstract implicit construct, condition not a hash"
+ ) if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
+
+ my $collapsed_cond = (
+ $self->{cond}
+ ? $self->_collapse_cond($self->{cond})
+ : {}
+ );
+
+ # precendence must be given to passed values over values inherited from
+ # the cond, so the order here is important.
+ my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
+ while( my($col,$value) = each %implied ){
+ if(ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '='){
+ $new{$col} = $value->{'='};
+ next;
+ }
+ $new{$col} = $value if $self->_is_deterministic_value($value);
+ }
+ }
+
+ %new = (
+ %new,
%{ $self->_remove_alias($values, $alias) },
- %{ $self->_remove_alias($collapsed_cond, $alias) },
-source_handle => $self->_source_handle,
-result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
);
return $self->result_class->new(\%new);
}
+# _is_deterministic_value
+#
+# Make an effor to strip non-deterministic values from the condition,
+# to make sure new_result chokes less
+
+sub _is_deterministic_value {
+ my $self = shift;
+ my $value = shift;
+ my $ref_type = ref $value;
+ return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
+ return 1 if Scalar::Util::blessed($value);
+ return 0;
+}
+
# _collapse_cond
#
# Recursively collapse the condition.
return \%unaliased;
}
+=head2 as_query
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \[ $sql, @bind ]
+
+=back
+
+Returns the SQL query and bind vars associated with the invocant.
+
+This is generally used as the RHS for a subquery.
+
+=cut
+
+sub as_query { return shift->cursor->as_query(@_) }
+
=head2 find_or_new
=over 4
=item Arguments: \%vals, \%attrs?
-=item Return Value: $object
+=item Return Value: $rowobject
=back
-Find an existing record from this resultset. If none exists, instantiate a new
-result object and return it. The object will not be saved into your storage
+ my $artist = $schema->resultset('Artist')->find_or_new(
+ { artist => 'fred' }, { key => 'artists' });
+
+ $cd->cd_to_producer->find_or_new({ producer => $producer },
+ { key => 'primary });
+
+Find an existing record from this resultset, based on its primary
+key, or a unique constraint. If none exists, instantiate a new result
+object and return it. The object will not be saved into your storage
until you call L<DBIx::Class::Row/insert> on it.
+You most likely want this method when looking for existing rows using
+a unique constraint that is not the primary key, or looking for
+related rows.
+
If you want objects to be saved immediately, use L</find_or_create> instead.
+B<Note>: C<find_or_new> is probably not what you want when creating a
+new row in a table that uses primary keys supplied by the
+database. Passing in a primary key column with a value of I<undef>
+will cause L</find> to attempt to search for a row with a value of
+I<NULL>.
+
=cut
sub find_or_new {
=item Arguments: \%vals
-=item Return Value: $object
+=item Return Value: a L<DBIx::Class::Row> $object
=back
-Inserts a record into the resultset and returns the object representing it.
+Attempt to create a single new row or a row with multiple related rows
+in the table represented by the resultset (and related tables). This
+will not check for duplicate rows before inserting, use
+L</find_or_create> to do that.
+
+To create one row for this resultset, pass a hashref of key/value
+pairs representing the columns of the table and the values you wish to
+store. If the appropriate relationships are set up, foreign key fields
+can also be passed an object representing the foreign row, and the
+value will be set to its primary key.
+
+To create related objects, pass a hashref for the value if the related
+item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
+and use the name of the relationship as the key. (NOT the name of the field,
+necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
+of hashrefs containing the data for each of the rows to create in the foreign
+tables, again using the relationship name as the key.
+
+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.
Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
+Example of creating a new row.
+
+ $person_rs->create({
+ name=>"Some Person",
+ email=>"somebody@someplace.com"
+ });
+
+Example of creating a new row and also creating rows in a related C<has_many>
+or C<has_one> resultset. Note Arrayref.
+
+ $artist_rs->create(
+ { artistid => 4, name => 'Manufactured Crap', cds => [
+ { title => 'My First CD', year => 2006 },
+ { title => 'Yet More Tweeny-Pop crap', year => 2007 },
+ ],
+ },
+ );
+
+Example of creating a new row and also creating a row in a related
+C<belongs_to>resultset. Note Hashref.
+
+ $cd_rs->create({
+ title=>"Music for Silly Walks",
+ year=>2000,
+ artist => {
+ name=>"Silly Musician",
+ }
+ });
+
=cut
sub create {
=item Arguments: \%vals, \%attrs?
-=item Return Value: $object
+=item Return Value: $rowobject
=back
- $class->find_or_create({ key => $val, ... });
+ $cd->cd_to_producer->find_or_create({ producer => $producer },
+ { key => 'primary });
-Tries to find a record based on its primary key or unique constraint; if none
+Tries to find a record based on its primary key or unique constraints; if none
is found, creates one and returns that instead.
my $cd = $schema->resultset('CD')->find_or_create({
{ key => 'cd_artist_title' }
);
+B<Note>: Because find_or_create() reads from the database and then
+possibly inserts based on the result, this method is subject to a race
+condition. Another process could create a record in the table after
+the find has completed and before the create has started. To avoid
+this problem, use find_or_create() inside a transaction.
+
+B<Note>: C<find_or_create> is probably not what you want when creating
+a new row in a table that uses primary keys supplied by the
+database. Passing in a primary key column with a value of I<undef>
+will cause L</find> to attempt to search for a row with a value of
+I<NULL>.
+
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>.
=item Arguments: \%col_values, { key => $unique_constraint }?
-=item Return Value: $object
+=item Return Value: $rowobject
=back
- $class->update_or_create({ col => $val, ... });
+ $resultset->update_or_create({ col => $val, ... });
First, searches for an existing row matching one of the unique constraints
(including the primary key) on the source of this resultset. If a row is
{ key => 'cd_artist_title' }
);
+ $cd->cd_to_producer->update_or_create({
+ producer => $producer,
+ name => 'harry',
+ }, {
+ key => 'primary,
+ });
+
+
If no C<key> is specified, it searches on all unique constraints defined on the
source, including the primary key.
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>.
+B<Note>: C<update_or_create> is probably not what you want when
+looking for a row in a table that uses primary keys supplied by the
+database, unless you actually have a key value. Passing in a primary
+key column with a value of I<undef> will cause L</find> to attempt to
+search for a row with a value of I<NULL>.
+
=cut
sub update_or_create {
Gets the contents of the cache for the resultset, if the cache is set.
+The cache is populated either by using the L</prefetch> attribute to
+L</search> or by calling L</set_cache>.
+
=cut
sub get_cache {
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
+L</prefetch> attribute to L</search>.
+
=cut
sub set_cache {
my $rel_obj = $self->result_source->relationship_info($rel);
$self->throw_exception(
- "search_related: result source '" . $self->_source_handle->source_moniker .
+ "search_related: result source '" . $self->result_source->source_name .
"' has no such relationship $rel")
unless $rel_obj;
#XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
my %attrs = %{$self->{attrs}||{}};
- delete $attrs{result_class};
+ delete @attrs{qw(result_class alias)};
my $new_cache;
}
}
- my $new = $self->_source_handle
- ->schema
- ->resultset($rel_obj->{class})
- ->search_rs(
- undef, {
- %attrs,
- join => undef,
- prefetch => undef,
- select => undef,
- as => undef,
- alias => $alias,
- where => $self->{cond},
- seen_join => $seen,
- from => $from,
- });
+ my $rel_source = $self->result_source->related_source($rel);
+
+ my $new = do {
+
+ # The reason we do this now instead of passing the alias to the
+ # search_rs below is that if you wrap/overload resultset on the
+ # source you need to know what alias it's -going- to have for things
+ # to work sanely (e.g. RestrictWithObject wants to be able to add
+ # extra query restrictions, and these may need to be $alias.)
+
+ my $attrs = $rel_source->resultset_attributes;
+ local $attrs->{alias} = $alias;
+
+ $rel_source->resultset
+ ->search_rs(
+ undef, {
+ %attrs,
+ join => undef,
+ prefetch => undef,
+ select => undef,
+ as => undef,
+ where => $self->{cond},
+ seen_join => $seen,
+ from => $from,
+ });
+ };
$new->set_cache($new_cache) if $new_cache;
$new;
};
}
+=head2 current_source_alias
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $source_alias
+
+=back
+
+Returns the current table alias for the result source this resultset is built
+on, that will be used in the SQL query. Usually it is C<me>.
+
+Currently the source alias that refers to the result set returned by a
+L</search>/L</find> family method depends on how you got to the resultset: it's
+C<me> by default, but eg. L</search_related> aliases it to the related result
+source name (and keeps C<me> referring to the original result set). The long
+term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
+(and make this method unnecessary).
+
+Thus it's currently necessary to use this method in predefined queries (see
+L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
+source alias of the current result set:
+
+ # in a result set class
+ sub modified_by {
+ my ($self, $user) = @_;
+
+ my $me = $self->current_source_alias;
+
+ return $self->search(
+ "$me.modified" => $user->id,
+ );
+ }
+
+=cut
+
+sub current_source_alias {
+ my ($self) = @_;
+
+ return ($self->{attrs} || {})->{alias} || 'me';
+}
+
sub _resolve_from {
my ($self, $extra_join) = @_;
my $source = $self->result_source;
my $join = ($attrs->{join}
? [ $attrs->{join}, $extra_join ]
: $extra_join);
+
+ # we need to take the prefetch the attrs into account before we
+ # ->resolve_join as otherwise they get lost - captainL
+ my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
+
$from = [
@$from,
- ($join ? $source->resolve_join($join, $attrs->{alias}, $seen) : ()),
+ ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
];
return ($from,$seen);
$join = $self->_merge_attr(
$join, $attrs->{prefetch}
);
+
}
$attrs->{from} = # have to copy here to avoid corrupting the original
@{$attrs->{from}},
$source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} })
];
+
}
$attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
}
$attrs->{collapse} = $collapse;
+ if ($attrs->{page}) {
+ $attrs->{offset} ||= 0;
+ $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
+ }
+
return $self->{_attrs} = $attrs;
}
-sub _merge_attr {
- my ($self, $a, $b) = @_;
- return $b unless defined($a);
- return $a unless defined($b);
+sub _rollout_attr {
+ my ($self, $attr) = @_;
- if (ref $b eq 'HASH' && ref $a eq 'HASH') {
- foreach my $key (keys %{$b}) {
- if (exists $a->{$key}) {
- $a->{$key} = $self->_merge_attr($a->{$key}, $b->{$key});
+ if (ref $attr eq 'HASH') {
+ return $self->_rollout_hash($attr);
+ } elsif (ref $attr eq 'ARRAY') {
+ return $self->_rollout_array($attr);
+ } else {
+ return [$attr];
+ }
+}
+
+sub _rollout_array {
+ my ($self, $attr) = @_;
+
+ my @rolled_array;
+ foreach my $element (@{$attr}) {
+ if (ref $element eq 'HASH') {
+ push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
+ } elsif (ref $element eq 'ARRAY') {
+ # XXX - should probably recurse here
+ push( @rolled_array, @{$self->_rollout_array($element)} );
+ } else {
+ push( @rolled_array, $element );
+ }
+ }
+ return \@rolled_array;
+}
+
+sub _rollout_hash {
+ my ($self, $attr) = @_;
+
+ my @rolled_array;
+ foreach my $key (keys %{$attr}) {
+ push( @rolled_array, { $key => $attr->{$key} } );
+ }
+ return \@rolled_array;
+}
+
+sub _calculate_score {
+ my ($self, $a, $b) = @_;
+
+ if (ref $b eq 'HASH') {
+ my ($b_key) = keys %{$b};
+ if (ref $a eq 'HASH') {
+ my ($a_key) = keys %{$a};
+ if ($a_key eq $b_key) {
+ return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
} else {
- $a->{$key} = $b->{$key};
+ return 0;
}
- }
- return $a;
+ } else {
+ return ($a eq $b_key) ? 1 : 0;
+ }
} else {
- $a = [$a] unless ref $a eq 'ARRAY';
- $b = [$b] unless ref $b eq 'ARRAY';
-
- my $hash = {};
- my @array;
- foreach my $x ($a, $b) {
- foreach my $element (@{$x}) {
- if (ref $element eq 'HASH') {
- $hash = $self->_merge_attr($hash, $element);
- } elsif (ref $element eq 'ARRAY') {
- push(@array, @{$element});
- } else {
- push(@array, $element) unless $b == $x
- && grep { $_ eq $element } @array;
- }
+ if (ref $a eq 'HASH') {
+ my ($a_key) = keys %{$a};
+ return ($b eq $a_key) ? 1 : 0;
+ } else {
+ return ($b eq $a) ? 1 : 0;
+ }
+ }
+}
+
+sub _merge_attr {
+ my ($self, $orig, $import) = @_;
+
+ return $import unless defined($orig);
+ return $orig unless defined($import);
+
+ $orig = $self->_rollout_attr($orig);
+ $import = $self->_rollout_attr($import);
+
+ my $seen_keys;
+ foreach my $import_element ( @{$import} ) {
+ # find best candidate from $orig to merge $b_element into
+ my $best_candidate = { position => undef, score => 0 }; my $position = 0;
+ foreach my $orig_element ( @{$orig} ) {
+ my $score = $self->_calculate_score( $orig_element, $import_element );
+ if ($score > $best_candidate->{score}) {
+ $best_candidate->{position} = $position;
+ $best_candidate->{score} = $score;
}
+ $position++;
}
-
- @array = grep { !exists $hash->{$_} } @array;
-
- return keys %{$hash}
- ? ( scalar(@array)
- ? [$hash, @array]
- : $hash
- )
- : \@array;
+ my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
+
+ if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
+ push( @{$orig}, $import_element );
+ } else {
+ my $orig_best = $orig->[$best_candidate->{position}];
+ # merge orig_best and b_element together and replace original with merged
+ if (ref $orig_best ne 'HASH') {
+ $orig->[$best_candidate->{position}] = $import_element;
+ } elsif (ref $import_element eq 'HASH') {
+ my ($key) = keys %{$orig_best};
+ $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
+ }
+ }
+ $seen_keys->{$import_key} = 1; # don't merge the same key twice
}
+
+ return $orig;
}
sub result_source {
sub throw_exception {
my $self=shift;
- $self->_source_handle->schema->throw_exception(@_);
+ if (ref $self && $self->_source_handle->schema) {
+ $self->_source_handle->schema->throw_exception(@_)
+ } else {
+ croak(@_);
+ }
+
}
# XXX: FIXME: Attributes docs need clearing up
specify an order. (The scalar ref causes it to be passed as raw sql to the DB,
so you will need to manually quote things as appropriate.)
+If your L<SQL::Abstract> version supports it (>=1.50), you can also use
+C<{-desc => 'year'}>, which takes care of the quoting for you. This is the
+recommended syntax.
+
=head2 columns
=over 4
=over 4
Indicates additional columns to be selected from storage. Works the same as
-L<select> but adds columns to the selection.
+L</select> but adds columns to the selection.
=back
=over 4
-Indicates additional column names for those added via L<+select>.
+Indicates additional column names for those added via L</+select>.
=back
=back
-Indicates column names for object inflation. That is, c< as >
+Indicates column names for object inflation. That is, C<as>
indicates the name that the column can be accessed as via the
C<get_column> method (or via the object accessor, B<if one already
-exists>). It has nothing to do with the SQL code C< SELECT foo AS bar
->.
+exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
-The C< as > attribute is used in conjunction with C<select>,
+The C<as> attribute is used in conjunction with C<select>,
usually when C<select> contains one or more function or stored
procedure names:
If you want to fetch related objects from other tables as well, see C<prefetch>
below.
+For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
+
=head2 prefetch
=over 4
=back
-Contains one or more relationships that should be fetched along with the main
-query (when they are accessed afterwards they will have already been
-"prefetched"). This is useful for when you know you will need the related
-objects, because it saves at least one query:
+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:
my $rs = $schema->resultset('Tag')->search(
undef,
case.
Simple prefetches will be joined automatically, so there is no need
-for a C<join> attribute in the above search. If you're prefetching to
-depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
-specify the join as well.
+for a C<join> attribute in the above search.
C<prefetch> can be used with the following relationship types: C<belongs_to>,
C<has_one> (or if you're using C<add_relationship>, any relationship declared
-with an accessor type of 'single' or 'filter').
+with an accessor type of 'single' or 'filter'). A more complex example that
+prefetches an artists cds, the tracks on those cds, and the tags associted
+with that artist is given below (assuming many-to-many from artists to tags):
+
+ my $rs = $schema->resultset('Artist')->search(
+ undef,
+ {
+ prefetch => [
+ { cds => 'tracks' },
+ { artist_tags => 'tags' }
+ ]
+ }
+ );
+
+
+B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
+attributes will be ignored.
=head2 page
# SELECT child.* FROM person child
# INNER JOIN person father ON child.father_id = father.id
+If you need to express really complex joins or you need a subselect, you
+can supply literal SQL to C<from> via a scalar reference. In this case
+the contents of the scalar will replace the table name asscoiated with the
+resultsource.
+
+WARNING: This technique might very well not work as expected on chained
+searches - you have been warned.
+
+ # Assuming the Event resultsource is defined as:
+
+ MySchema::Event->add_columns (
+ sequence => {
+ data_type => 'INT',
+ is_auto_increment => 1,
+ },
+ location => {
+ data_type => 'INT',
+ },
+ type => {
+ data_type => 'INT',
+ },
+ );
+ MySchema::Event->set_primary_key ('sequence');
+
+ # This will get back the latest event for every location. The column
+ # selector is still provided by DBIC, all we do is add a JOIN/WHERE
+ # combo to limit the resultset
+
+ $rs = $schema->resultset('Event');
+ $table = $rs->result_source->name;
+ $latest = $rs->search (
+ undef,
+ { from => \ "
+ (SELECT e1.* FROM $table e1
+ JOIN $table e2
+ ON e1.location = e2.location
+ AND e1.sequence < e2.sequence
+ WHERE e2.sequence is NULL
+ ) me",
+ },
+ );
+
+ # Equivalent SQL (with the DBIC chunks added):
+
+ SELECT me.sequence, me.location, me.type FROM
+ (SELECT e1.* FROM events e1
+ JOIN events e2
+ ON e1.location = e2.location
+ AND e1.sequence < e2.sequence
+ WHERE e2.sequence is NULL
+ ) me;
+
+=head2 for
+
+=over 4
+
+=item Value: ( 'update' | 'shared' )
+
+=back
+
+Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
+... FOR SHARED.
+
=cut
1;
projects / dbsrgits/DBIx-Class.git / blobdiff