X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=7f53ec3dca5c8745fab92245cc54b3ff6ada7400;hb=9901aad73ff9dc45b426534fe406c102fb9fb77c;hp=4f9bb927fc93cddc095f0495825d87d65a51749d;hpb=e60dc79fcd4d6318e83584b826526e65048b86a9;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index 4f9bb92..7f53ec3 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -11,48 +11,152 @@ 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 -DBIx::Class::ResultSet - Responsible for fetching and creating resultset. +DBIx::Class::ResultSet - Represents a query used for fetching a set of results. =head1 SYNOPSIS - my $rs = $schema->resultset('User')->search(registered => 1); - my @rows = $schema->resultset('CD')->search(year => 2005); + my $users_rs = $schema->resultset('User'); + my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 }); + my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all(); =head1 DESCRIPTION -The resultset is also known as an iterator. It is responsible for handling -queries that may return an arbitrary number of rows, e.g. via L -or a C relationship. +A ResultSet is an object which stores a set of conditions representing +a query. It is the backbone of DBIx::Class (i.e. the really +important/useful bit). -In the examples below, the following table classes are used: +No SQL is executed on the database when a ResultSet is created, it +just stores all the conditions needed to create the query. - package MyApp::Schema::Artist; - use base qw/DBIx::Class/; - __PACKAGE__->load_components(qw/Core/); - __PACKAGE__->table('artist'); - __PACKAGE__->add_columns(qw/artistid name/); - __PACKAGE__->set_primary_key('artistid'); - __PACKAGE__->has_many(cds => 'MyApp::Schema::CD'); - 1; +A basic ResultSet representing the data of an entire table is returned +by calling C on a L and passing in a +L name. - package MyApp::Schema::CD; - use base qw/DBIx::Class/; - __PACKAGE__->load_components(qw/Core/); - __PACKAGE__->table('cd'); - __PACKAGE__->add_columns(qw/cdid artist title year/); - __PACKAGE__->set_primary_key('cdid'); - __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist'); - 1; + my $users_rs = $schema->resultset('User'); + +A new ResultSet is returned from calling L on an existing +ResultSet. The new one will contain all the conditions of the +original, plus any new conditions added in the C call. + +A ResultSet is also an iterator. L is used to return all the +Ls the ResultSet represents. + +The query that the ResultSet represents is B executed against +the database when these methods are called: + +=over + +=item L + +=item L + +=item L + +=item L + +=item L + +=item L + +=back + +=head1 EXAMPLES + +=head2 Chaining resultsets + +Let's say you've got a query that needs to be run to return some data +to the user. But, you have an authorization system in place that +prevents certain users from seeing certain information. So, you want +to construct the basic query in one method, but add constraints to it in +another. + + sub get_data { + my $self = shift; + my $request = $self->get_request; # Get a request object somehow. + my $schema = $self->get_schema; # Get the DBIC schema object somehow. + + my $cd_rs = $schema->resultset('CD')->search({ + title => $request->param('title'), + year => $request->param('year'), + }); + + $self->apply_security_policy( $cd_rs ); + + return $cd_rs->all(); + } + + sub apply_security_policy { + my $self = shift; + my ($rs) = @_; + + return $rs->search({ + subversive => 0, + }); + } + +=head3 Resolving conditions and attributes + +When a resultset is chained from another resultset, conditions and +attributes with the same keys need resolving. + +L, L, L, L attributes are merged +into the existing ones from the original resultset. + +The L, L attribute, and any search conditions are +merged with an SQL C to the existing condition from the original +resultset. + +All other attributes are overridden by any new ones supplied in the +search attributes. + +=head2 Multiple queries + +Since a resultset just defines a query, you can do all sorts of +things with it with the same object. + + # Don't hit the DB yet. + my $cd_rs = $schema->resultset('CD')->search({ + title => 'something', + year => 2009, + }); + + # Each of these hits the DB individually. + my $count = $cd_rs->count; + my $most_recent = $cd_rs->get_column('date_released')->max(); + my @records = $cd_rs->all; + +And it's not just limited to SELECT statements. + + $cd_rs->delete(); + +This is even cooler: + + $cd_rs->create({ artist => 'Fred' }); + +Which is the same as: + + $schema->resultset('CD')->create({ + title => 'something', + year => 2009, + artist => 'Fred' + }); + +See: L, L, L, L, L. =head1 OVERLOADING -If a resultset is used as a number it returns the C. However, if it is used as a boolean it is always true. So if you want to check if a result set has any results use C. C will always be true. +If a resultset is used in a numeric context it returns the L. +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. +C will always be true. =head1 METHODS @@ -99,9 +203,10 @@ sub new { $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, @@ -110,6 +215,10 @@ sub new { bless $self, $class; + $self->result_class( + $attrs->{result_class} || $source->resolve->result_class + ); + return $self; } @@ -142,6 +251,8 @@ L. For more examples of using this function, see L. For a complete documentation for the first argument, see L. +For more help on using joins with search, see L. + =cut sub search { @@ -168,10 +279,9 @@ always return a resultset, even in list context. sub search_rs { my $self = shift; - my $rows; - - unless (@_) { # no search, effectively just a clone - $rows = $self->get_cache; + # Special-case handling for (undef, undef). + if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) { + pop(@_); pop(@_); } my $attrs = {}; @@ -180,10 +290,24 @@ sub search_rs { 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}); } @@ -268,13 +392,30 @@ sub search_rs { Pass a literal chunk of SQL to be added to the conditional part of the resultset query. +CAVEAT: C is provided for Class::DBI compatibility and should +only be used in that context. C is a convenience method. +It is equivalent to calling $schema->search(\[]), but if you want to ensure +columns are bound correctly, use C. + +Example of how to use C instead of C + + 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 and +L for searching techniques that do not +require C. + =cut sub search_literal { - my ($self, $cond, @vals) = @_; - my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); - $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; - return $self->search(\$cond, $attrs); + my ($self, $sql, @bind) = @_; + my $attr; + if ( @bind && ref($bind[-1]) eq 'HASH' ) { + $attr = pop @bind; + } + return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () )); } =head2 find @@ -283,7 +424,7 @@ sub search_literal { =item Arguments: @values | \%cols, \%attrs? -=item Return Value: $row_object +=item Return Value: $row_object | undef =back @@ -312,11 +453,18 @@ Additionally, you can specify the columns explicitly by name: If the C is specified as C, it searches only on the primary key. If no C is specified, it searches on all unique constraints defined on the -source, including the primary key. +source for which column data is provided, including the primary key. If your table does not have a primary key, you B provide a value for the C attribute matching one of the unique constraints on the source. +In addition to C, L recognizes and applies standard +L in the same way as L does. + +Note: If your query does not return only one row, a warning is generated: + + Query returned more than one row + See also L and L. For information on how to declare unique constraints, see L. @@ -368,25 +516,46 @@ sub find { @{$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); + } } } @@ -476,6 +645,17 @@ sub search_related { 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 @@ -513,16 +693,38 @@ 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 + +=item B + +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: -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 $rs returned from that. + Query returned more than one row + +In this case, you should be using L or L instead, or if you really +know what you are doing, use the L attribute to explicitly limit the size +of the resultset. + +=back =cut sub single { my ($self, $where) = @_; + if(@_ > 2) { + $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()'); + } + my $attrs = { %{$self->_resolved_attrs} }; if ($where) { if (defined $attrs->{where}) { @@ -653,15 +855,29 @@ 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. +This method is deprecated and will be removed in 0.09. Use L +instead. An example conversion is: + + ->search_like({ foo => 'bar' }); + + # Becomes + + ->search({ foo => { like => 'bar' } }); + =cut sub search_like { my $class = shift; + carp join ("\n", + 'search_like() is deprecated and will be removed in 0.09.', + 'Instead use ->search({ x => { -like => "y%" } })', + '(note the outer pair of {}s - they are important!)' + ); my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_}; $query->{$_} = { 'like' => $query->{$_} } for keys %$query; @@ -905,8 +1121,21 @@ An accessor for the class to use when creating row objects. Defaults to C<< result_source->result_class >> - which in most cases is the name of the L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class. +Note that changing the result_class will also remove any components +that were originally loaded in the source class via +L. Any overloaded methods +in the original source class will not run. + =cut +sub result_class { + my ($self, $result_class) = @_; + if ($result_class) { + $self->ensure_class_loaded($result_class); + $self->_result_class($result_class); + } + $self->_result_class; +} =head2 count @@ -922,7 +1151,7 @@ Performs an SQL C with the same query as the resultset was built 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 with C, L emulates C +Note: When using C with C, L emulates C using C. Some databases (notably SQLite) do not support C with multiple columns. If you are using such a database, you should only use columns from the main table in your C @@ -975,7 +1204,7 @@ sub _count { # Separated out so pager can get the full 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 $count; } @@ -1017,7 +1246,11 @@ is returned in list context. =cut sub all { - my ($self) = @_; + my $self = shift; + if(@_) { + $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()"); + } + return @{ $self->get_cache } if $self->get_cache; my @obj; @@ -1169,6 +1402,11 @@ sub update { $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; + carp( 'WARNING! Currently $rs->update() does not generate proper SQL' + . ' on joined resultsets, and may affect 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; return $self->result_source->storage->update( @@ -1215,11 +1453,26 @@ 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); @@ -1255,11 +1508,12 @@ 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. +to insert the data, as this is a faster method. Otherwise, each set of data is inserted into the database using L, and a arrayref of the resulting row @@ -1297,10 +1551,32 @@ 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: + + $Arstist_rs->populate([ + [qw/artistid name/], + [100, 'A Formally Unknown Singer'], + [101, 'A singer that jumped the shark two albums ago'], + [102, 'An actually cool singer.'], + ]); + +Please note an important effect on your data when choosing between void and +wantarray context. Since void context goes straight to C in +L this will skip any component that is overriding +c. So if you are using something like L to +create primary keys for you, you will find that your PKs are empty. In this +case you will have to use the wantarray context in order to create those +values. + =cut sub populate { - my ($self, $data) = @_; + my $self = shift @_; + my $data = ref $_[0][0] eq 'HASH' + ? $_[0] : ref $_[0][0] eq 'ARRAY' ? $self->_normalize_populate_args($_[0]) : + $self->throw_exception('Populate expects an arrayref of hashes or arrayref of arrayrefs'); if(defined wantarray) { my @created; @@ -1374,6 +1650,28 @@ sub populate { } } +=head2 _normalize_populate_args ($args) + +Private method used by L to normalize its 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[$index]; + } + push @results_to_create, \%result_to_create; + } + return \@results_to_create; +} + =head2 pager =over 4 @@ -1387,6 +1685,9 @@ sub populate { Return Value a L object for the current resultset. Only makes sense for queries with a C attribute. +To get the full count of entries for a paged resultset, call +C on the L object. + =cut sub pager { @@ -1417,7 +1718,7 @@ attribute set on the resultset (10 by default). sub page { my ($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 @@ -1426,11 +1727,16 @@ sub page { =item Arguments: \%vals -=item Return Value: $object +=item Return Value: $rowobject =back -Creates an object in the resultset's result class and returns it. +Creates a new row object in the resultset's result class and returns +it. The row is not inserted into the database at this point, call +L to do that. Calling L +will tell you whether the row object has been inserted or not. + +Passes the hashref of input on to L. =cut @@ -1438,15 +1744,42 @@ sub new_result { my ($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} || {} }; # nothing might have been inserted yet + $new{-from_resultset} = [ keys %new ] if keys %new; + } 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 ); @@ -1454,6 +1787,20 @@ sub new_result { 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. @@ -1512,22 +1859,59 @@ sub _remove_alias { return \%unaliased; } +=head2 as_query (EXPERIMENTAL) + +=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. + +B: This feature is still experimental. + +=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 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 { @@ -1544,14 +1928,63 @@ sub find_or_new { =item Arguments: \%vals -=item Return Value: $object +=item Return Value: a L $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 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), +and use the name of the relationship as the key. (NOT the name of the field, +necessarily). For C and C 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), 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 +or C 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 +Cresultset. Note Hashref. + + $cd_rs->create({ + title=>"Music for Silly Walks", + year=>2000, + artist => { + name=>"Silly Musician", + } + }); + =cut sub create { @@ -1567,13 +2000,14 @@ 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({ @@ -1594,6 +2028,18 @@ constraint. For example: { key => 'cd_artist_title' } ); +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. @@ -1613,11 +2059,11 @@ 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 @@ -1637,6 +2083,14 @@ 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. @@ -1645,6 +2099,12 @@ 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 { @@ -1661,6 +2121,63 @@ sub update_or_create { return $self->create($cond); } +=head2 update_or_new + +=over 4 + +=item Arguments: \%col_values, { key => $unique_constraint }? + +=item Return Value: $rowobject + +=back + + $resultset->update_or_new({ 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 +found, updates it with the other given column values. Otherwise, instantiate +a new result object and return it. The object will not be saved into your storage +until you call L on it. + +Takes an optional C attribute to search on a specific unique constraint. +For example: + + # In your application + my $cd = $schema->resultset('CD')->update_or_new( + { + artist => 'Massive Attack', + title => 'Mezzanine', + year => 1998, + }, + { key => 'cd_artist_title' } + ); + + if ($cd->in_storage) { + # the cd was updated + } + else { + # the cd is not yet in the database, let's insert it + $cd->insert; + } + +See also L, L and L. + +=cut + +sub update_or_new { + my $self = shift; + my $attrs = ( @_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {} ); + my $cond = ref $_[0] eq 'HASH' ? shift : {@_}; + + my $row = $self->find( $cond, $attrs ); + if ( defined $row ) { + $row->update($cond); + return $row; + } + + return $self->new_result($cond); +} + =head2 get_cache =over 4 @@ -1673,6 +2190,9 @@ 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 attribute to +L or by calling L. + =cut sub get_cache { @@ -1694,6 +2214,9 @@ of objects of the same class as those produced by the resultset. Note that 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 attribute to L. + =cut sub set_cache { @@ -1745,7 +2268,7 @@ sub related_resultset { 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 $rel_obj; @@ -1756,7 +2279,7 @@ sub related_resultset { #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi my %attrs = %{$self->{attrs}||{}}; - delete $attrs{result_class}; + delete @attrs{qw(result_class alias)}; my $new_cache; @@ -1767,26 +2290,80 @@ sub related_resultset { } } - 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: $source_alias + +=back + +Returns the current table alias for the result source this resultset is built +on, that will be used in the SQL query. Usually it is C. + +Currently the source alias that refers to the result set returned by a +L/L family method depends on how you got to the resultset: it's +C by default, but eg. L aliases it to the related result +source name (and keeps C referring to the original result set). The long +term goal is to make L always alias the current resultset as C +(and make this method unnecessary). + +Thus it's currently necessary to use this method in predefined queries (see +L) when referring to the +source alias of the current result set: + + # in a result set class + sub modified_by { + my ($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; @@ -1817,97 +2394,135 @@ sub _resolved_attrs { my $self = shift; return $self->{_attrs} if $self->{_attrs}; - my $attrs = { %{$self->{attrs}||{}} }; + my $attrs = { %{ $self->{attrs} || {} } }; my $source = $self->result_source; - my $alias = $attrs->{alias}; + my $alias = $attrs->{alias}; $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols}; - if ($attrs->{columns}) { - delete $attrs->{as}; - } elsif (!$attrs->{select}) { - $attrs->{columns} = [ $source->columns ]; + my @colbits; + + # build columns (as long as select isn't set) into a set of as/select hashes + unless ( $attrs->{select} ) { + @colbits = map { + ( ref($_) eq 'HASH' ) + ? $_ + : { + ( + /^\Q${alias}.\E(.+)$/ + ? "$1" + : "$_" + ) + => + ( + /\./ + ? "$_" + : "${alias}.$_" + ) + } + } ( ref($attrs->{columns}) eq 'ARRAY' ) ? @{ delete $attrs->{columns}} : (delete $attrs->{columns} || $source->columns ); } - - $attrs->{select} = - ($attrs->{select} - ? (ref $attrs->{select} eq 'ARRAY' - ? [ @{$attrs->{select}} ] - : [ $attrs->{select} ]) - : [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ] - ); - $attrs->{as} = - ($attrs->{as} - ? (ref $attrs->{as} eq 'ARRAY' - ? [ @{$attrs->{as}} ] - : [ $attrs->{as} ]) - : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ] + # add the additional columns on + foreach ( 'include_columns', '+columns' ) { + push @colbits, map { + ( ref($_) eq 'HASH' ) + ? $_ + : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) } + } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} ); + } + + # start with initial select items + if ( $attrs->{select} ) { + $attrs->{select} = + ( ref $attrs->{select} eq 'ARRAY' ) + ? [ @{ $attrs->{select} } ] + : [ $attrs->{select} ]; + $attrs->{as} = ( + $attrs->{as} + ? ( + ref $attrs->{as} eq 'ARRAY' + ? [ @{ $attrs->{as} } ] + : [ $attrs->{as} ] + ) + : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ] ); - - my $adds; - if ($adds = delete $attrs->{include_columns}) { - $adds = [$adds] unless ref $adds eq 'ARRAY'; - push(@{$attrs->{select}}, @$adds); - push(@{$attrs->{as}}, map { m/([^.]+)$/; $1 } @$adds); } - if ($adds = delete $attrs->{'+select'}) { + else { + + # otherwise we intialise select & as to empty + $attrs->{select} = []; + $attrs->{as} = []; + } + + # now add colbits to select/as + push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits ); + push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits ); + + my $adds; + if ( $adds = delete $attrs->{'+select'} ) { $adds = [$adds] unless ref $adds eq 'ARRAY'; - push(@{$attrs->{select}}, - map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds); + push( + @{ $attrs->{select} }, + map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds + ); } - if (my $adds = delete $attrs->{'+as'}) { + if ( $adds = delete $attrs->{'+as'} ) { $adds = [$adds] unless ref $adds eq 'ARRAY'; - push(@{$attrs->{as}}, @$adds); + push( @{ $attrs->{as} }, @$adds ); } - $attrs->{from} ||= [ { 'me' => $source->from } ]; + $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ]; - if (exists $attrs->{join} || exists $attrs->{prefetch}) { + if ( exists $attrs->{join} || exists $attrs->{prefetch} ) { my $join = delete $attrs->{join} || {}; - if (defined $attrs->{prefetch}) { - $join = $self->_merge_attr( - $join, $attrs->{prefetch} - ); - + if ( defined $attrs->{prefetch} ) { + $join = $self->_merge_attr( $join, $attrs->{prefetch} ); + } - $attrs->{from} = # have to copy here to avoid corrupting the original + $attrs->{from} = # have to copy here to avoid corrupting the original [ - @{$attrs->{from}}, - $source->resolve_join($join, $alias, { %{$attrs->{seen_join}||{}} }) + @{ $attrs->{from} }, + $source->resolve_join( + $join, $alias, { %{ $attrs->{seen_join} || {} } } + ) ]; } - $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct}; - if ($attrs->{order_by}) { - $attrs->{order_by} = (ref($attrs->{order_by}) eq 'ARRAY' - ? [ @{$attrs->{order_by}} ] - : [ $attrs->{order_by} ]); - } else { - $attrs->{order_by} = []; + $attrs->{group_by} ||= $attrs->{select} + if delete $attrs->{distinct}; + if ( $attrs->{order_by} ) { + $attrs->{order_by} = ( + ref( $attrs->{order_by} ) eq 'ARRAY' + ? [ @{ $attrs->{order_by} } ] + : [ $attrs->{order_by} ] + ); + } + else { + $attrs->{order_by} = []; } my $collapse = $attrs->{collapse} || {}; - if (my $prefetch = delete $attrs->{prefetch}) { - $prefetch = $self->_merge_attr({}, $prefetch); + if ( my $prefetch = delete $attrs->{prefetch} ) { + $prefetch = $self->_merge_attr( {}, $prefetch ); my @pre_order; - my $seen = $attrs->{seen_join} || {}; - foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) { + my $seen = { %{ $attrs->{seen_join} || {} } }; + foreach my $p ( ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch) ) { + # bring joins back to level of current class - my @prefetch = $source->resolve_prefetch( - $p, $alias, $seen, \@pre_order, $collapse - ); - push(@{$attrs->{select}}, map { $_->[0] } @prefetch); - push(@{$attrs->{as}}, map { $_->[1] } @prefetch); + my @prefetch = + $source->resolve_prefetch( $p, $alias, $seen, \@pre_order, $collapse ); + push( @{ $attrs->{select} }, map { $_->[0] } @prefetch ); + push( @{ $attrs->{as} }, map { $_->[1] } @prefetch ); } - push(@{$attrs->{order_by}}, @pre_order); + push( @{ $attrs->{order_by} }, @pre_order ); } $attrs->{collapse} = $collapse; - if ($attrs->{page}) { + if ( $attrs->{page} ) { $attrs->{offset} ||= 0; - $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); + $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) ); } return $self->{_attrs} = $attrs; @@ -1978,43 +2593,44 @@ sub _calculate_score { } sub _merge_attr { - my ($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} : ($b_element); - if ($best_candidate->{score} == 0 || exists $seen_keys->{$b_key}) { - push( @{$a}, $b_element ); + my ($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 { - $seen_keys->{$b_key} = 1; # don't merge the same key twice - 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}) }; } } + $seen_keys->{$import_key} = 1; # don't merge the same key twice } - return $a; + return $orig; } sub result_source { @@ -2035,32 +2651,49 @@ See L for details. sub throw_exception { my $self=shift; - $self->_source_handle->schema->throw_exception(@_); + if (ref $self && $self->_source_handle->schema) { + $self->_source_handle->schema->throw_exception(@_) + } else { + croak(@_); + } + } # XXX: FIXME: Attributes docs need clearing up =head1 ATTRIBUTES -The resultset takes various attributes that modify its behavior. Here's an -overview of them: +Attributes are used to refine a ResultSet in various ways when +searching for data. They can be passed to any method which takes an +C<\%attrs> argument. See L, L, L, +L. + +These are in no particular order: =head2 order_by =over 4 -=item Value: ($order_by | \@order_by) +=item Value: ( $order_by | \@order_by | \%order_by ) =back -Which column(s) to order the results by. This is currently passed -through directly to SQL, so you can give e.g. C for a -descending order on the column `year'. +Which column(s) to order the results by. If a single column name, or +an arrayref of names is supplied, the argument is passed through +directly to SQL. The hashref syntax allows for connection-agnostic +specification of ordering direction: -Please note that if you have C enabled (see -L) you will need to do C<\'year DESC' > to -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.) + For descending order: + + order_by => { -desc => [qw/col1 col2 col3/] } + + For explicit ascending order: + + order_by => { -asc => 'col' } + +The old scalarref syntax (i.e. order_by => \'year DESC') is still +supported, although you are strongly encouraged to use the hashref +syntax as outlined above. =head2 columns @@ -2070,12 +2703,15 @@ so you will need to manually quote things as appropriate.) =back -Shortcut to request a particular set of columns to be retrieved. Adds -C onto the start of any column without a C<.> in it and sets C as normal. (You may also -use the C attribute, as in earlier versions of DBIC.) +Shortcut to request a particular set of columns to be retrieved. Each +column spec may be a string (a table column name), or a hash (in which +case the key is the C value, and the value is used as the C from that, then auto-populates C from +C but adds columns to the selection. +L but adds columns to the selection. =back @@ -2132,7 +2781,7 @@ L. -The C< as > attribute is used in conjunction with C, usually when C +attributes will be ignored. =head2 page @@ -2309,6 +2974,10 @@ on it. If L attribute is not specified it defualts to 10 rows per page. +When you have a paged resultset, L will only return the number +of rows in the page. To get the total, use the L and call +C on it. + =head2 rows =over 4 @@ -2506,6 +3175,69 @@ 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 + +=item Value: ( 'update' | 'shared' ) + +=back + +Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT +... FOR SHARED. + =cut 1;