X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=4e8467eaad5bc96bb67136995511f7e8464323dc;hb=7e51afbf1951bc8febf00897e5e3f0f25dfc34aa;hp=11f275cacb2ad96a3654994687aa95769de538c0;hpb=68f3b0dd9e91421b02c818ca42543b79bc197dfd;p=dbsrgits%2FDBIx-Class-Historic.git diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index 11f275c..4e8467e 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -15,7 +15,7 @@ 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 @@ -108,7 +108,6 @@ sub new { # 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, @@ -117,6 +116,10 @@ sub new { bless $self, $class; + $self->result_class( + $attrs->{result_class} || $source->resolve->result_class + ); + return $self; } @@ -200,7 +203,7 @@ sub search_rs { 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}); } @@ -307,7 +310,7 @@ sub search_literal { =item Arguments: @values | \%cols, \%attrs? -=item Return Value: $row_object +=item Return Value: $row_object | undef =back @@ -341,6 +344,9 @@ source for which column data is provided, including the primary key. If your table does not have a primary key, you B provide a value for the C attribute matching one of the unique constraints on the source. +In addition to C, L recognizes and applies standard +L in the same way as L does. + Note: If your query does not return only one row, a warning is generated: Query returned more than one row @@ -573,19 +579,29 @@ sub cursor { 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 as an optimisation. +any records in it; if not returns nothing. Used by L as a lean version of +L. + +While this method can take an optional search condition (just like L) +being a fast-code-path it does not recognize search attributes. If you need to +add extra joins or similar, call L and then chain-call L on the +L returned. + +=over -Can optionally take an additional condition B - this is a fast-code-path -method; if you need to add extra joins or similar call L and then -L without a condition on the L returned from -that. +=item B -B: As of 0.08100, this method assumes that the query returns only one -row. If more than one row is returned, you will receive a warning: +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 or L instead. +In this case, you should be using L or L instead, or if you really +know what you are doing, use the L attribute to explicitly limit the size +of the resultset. + +=back =cut @@ -721,8 +737,8 @@ sub get_column { $cd_rs = $rs->search_like({ title => '%blue%'}); Performs a search, but uses C instead of C<=> as the condition. Note -that this is simply a convenience method. You most likely want to use -L with specific operators. +that this is simply a convenience method retained for ex Class::DBI users. +You most likely want to use L with specific operators. For more information, see L. @@ -975,6 +991,14 @@ L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class. =cut +sub result_class { + my ($self, $result_class) = @_; + if ($result_class) { + $self->ensure_class_loaded($result_class); + $self->_result_class($result_class); + } + $self->_result_class; +} =head2 count @@ -1283,11 +1307,26 @@ Deletes the contents of the resultset from its result source. Note that this will not run DBIC cascade triggers. See L if you need triggers to run. See also L. +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); @@ -1323,8 +1362,9 @@ sub delete_all { =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 in L is used to insert the data, as this is a faster method. @@ -1364,7 +1404,18 @@ Example: Assuming an Artist Class that has many CDs Classes relating: print $ArtistOne->name; ## response is 'Artist One' print $ArtistThree->cds->count ## reponse is '2' - + +For the arrayref of arrayrefs style, the first element should be a list of the +fieldsnames to which the remaining elements are rows being inserted. For +example: + + $Arstist_rs->populate([ + [qw/artistid name/], + [100, 'A Formally Unknown Singer'], + [101, 'A singer that jumped the shark two albums ago'], + [102, 'An actually cool singer.'], + ]); + Please note an important effect on your data when choosing between void and wantarray context. Since void context goes straight to C in L this will skip any component that is overriding @@ -1376,7 +1427,10 @@ values. =cut sub populate { - my ($self, $data) = @_; + my $self = shift @_; + my $data = ref $_[0][0] eq 'HASH' + ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) : + $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs'); if(defined wantarray) { my @created; @@ -1450,6 +1504,28 @@ sub populate { } } +=head2 _normalize_populate_args ($args) + +Private method used by L to normalize it's incoming arguments. Factored +out in case you want to subclass and accept new argument structures to the +L 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 @@ -1502,7 +1578,7 @@ sub page { =item Arguments: \%vals -=item Return Value: $object +=item Return Value: $rowobject =back @@ -1639,16 +1715,33 @@ sub _remove_alias { =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 it's 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 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 instead. +B: C 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 +will cause L to attempt to search for a row with a value of +I. + =cut sub find_or_new { @@ -1737,13 +1830,14 @@ 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({ @@ -1764,12 +1858,18 @@ constraint. For example: { key => 'cd_artist_title' } ); -Note: Because find_or_create() reads from the database and then +B: 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: C 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 +will cause L to attempt to search for a row with a value of +I. + See also L and L. For information on how to declare unique constraints, see L. @@ -1789,11 +1889,11 @@ sub find_or_create { =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 @@ -1813,6 +1913,14 @@ For example: { key => 'cd_artist_title' } ); + $cd->cd_to_producer->update_or_create({ + producer => $producer, + name => 'harry', + }, { + key => 'primary, + }); + + If no C is specified, it searches on all unique constraints defined on the source, including the primary key. @@ -1821,6 +1929,12 @@ If the C is specified as C, it searches only on the primary key. See also L and L. For information on how to declare unique constraints, see L. +B: C 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 will cause L to attempt to +search for a row with a value of I. + =cut sub update_or_create { @@ -1980,6 +2094,49 @@ sub related_resultset { }; } +=head2 current_source_alias + +=over 4 + +=item Arguments: none + +=item Return Value: $source_alias + +=back + +Returns the current table alias for the result source this resultset is built +on, that will be used in the SQL query. Usually it is C. + +Currently the source alias that refers to the result set returned by a +L/L family method depends on how you got to the resultset: it's +C by default, but eg. L aliases it to the related result +source name (and keeps C referring to the original result set). The long +term goal is to make L always alias the current resultset as C +(and make this method unnecessary). + +Thus it's currently necessary to use this method in predefined queries (see +L) when referring to the +source alias of the current result set: + + # in a result set class + sub modified_by { + my ($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 = $self->result_source; @@ -2171,44 +2328,44 @@ sub _calculate_score { } sub _merge_attr { - my ($self, $a, $b) = @_; + my ($self, $orig, $import) = @_; - return $b unless defined($a); - return $a unless defined($b); + return $import unless defined($orig); + return $orig unless defined($import); - $a = $self->_rollout_attr($a); - $b = $self->_rollout_attr($b); + $orig = $self->_rollout_attr($orig); + $import = $self->_rollout_attr($import); my $seen_keys; - foreach my $b_element ( @{$b} ) { - # find best candidate from $a to merge $b_element into + 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 $a_element ( @{$a} ) { - my $score = $self->_calculate_score( $a_element, $b_element ); + 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; } $position++; } - my ($b_key) = ( ref $b_element eq 'HASH' ) ? keys %{$b_element} : ($b_element); + my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element); - if ($best_candidate->{score} == 0 || exists $seen_keys->{$b_key}) { - push( @{$a}, $b_element ); + if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) { + push( @{$orig}, $import_element ); } else { - my $a_best = $a->[$best_candidate->{position}]; - # merge a_best and b_element together and replace original with merged - if (ref $a_best ne 'HASH') { - $a->[$best_candidate->{position}] = $b_element; - } elsif (ref $b_element eq 'HASH') { - my ($key) = keys %{$a_best}; - $a->[$best_candidate->{position}] = { $key => $self->_merge_attr($a_best->{$key}, $b_element->{$key}) }; + 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}) }; } } - $seen_keys->{$b_key} = 1; # don't merge the same key twice + $seen_keys->{$import_key} = 1; # don't merge the same key twice } - return $a; + return $orig; } sub result_source { @@ -2261,6 +2418,10 @@ L) you will need to do C<\'year DESC' > 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 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 @@ -2721,6 +2882,58 @@ with a father in the person table, we could explicitly use C: # 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 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