X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=c6a68c3a9846761065895402c1751a4f6450ff9c;hb=0e7a447e570daf41c11b403fd81046756894cc27;hp=7d413d753667e2a53c6a4a965889b762a95e4589;hpb=a780a0ff7c99dd9b640f8c29ad0466bd0c907bf3;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index 7d413d7..c6a68c3 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -249,7 +249,17 @@ For more help on using joins with search, see L. sub search { my $self = shift; my $rs = $self->search_rs( @_ ); - return (wantarray ? $rs->all : $rs); + + my $want = wantarray; + if ($want) { + return $rs->all; + } + elsif (defined $want) { + return $rs; + } + else { + $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense'); + } } =head2 search_rs @@ -408,25 +418,56 @@ sub search_literal { =over 4 -=item Arguments: @values | \%cols, \%attrs? +=item Arguments: \%columns_values | @pk_values, \%attrs? =item Return Value: $row_object | undef =back -Finds a row based on its primary key or unique constraint. For example, to find -a row by its primary key: +Finds and returns a single row based on supplied criteria. Takes either a +hashref with the same format as L (including inference of foreign +keys from related objects), or a list of primary key values in the same +order as the L +declaration on the L. + +In either case an attempt is made to combine conditions already existing on +the resultset with the condition passed to this method. + +To aid with preparing the correct query for the storage you may supply the +C attribute, which is the name of a +L (the +unique constraint corresponding to the +L is always named +C). If the C attribute has been supplied, and DBIC is unable +to construct a query that satisfies the named unique constraint fully ( +non-NULL values for each column member of the constraint) an exception is +thrown. + +If no C is specified, the search is carried over all unique constraints +which are fully defined by the available condition. + +If no such constraint is found, C currently defaults to a simple +C<< search->(\%column_values) >> which may or may not do what you expect. +Note that this fallback behavior may be deprecated in further versions. If +you need to search with arbitrary conditions - use L. If the query +resulting from this fallback produces more than one row, a warning to the +effect is issued, though only the first row is constructed and returned as +C<$row_object>. - my $cd = $schema->resultset('CD')->find(5); +In addition to C, L recognizes and applies standard +L in the same way as L does. -You can also find a row by a specific unique constraint using the C -attribute. For example: +Note that if you have extra concerns about the correctness of the resulting +query you need to specify the C attribute and supply the entire condition +as an argument to find (since it is not always possible to perform the +combination of the resultset condition with the supplied one, especially if +the resultset condition contains literal sql). - my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { - key => 'cd_artist_title' - }); +For example, to find a row by its primary key: -Additionally, you can specify the columns explicitly by name: + my $cd = $schema->resultset('CD')->find(5); + +You can also find a row by a specific unique constraint: my $cd = $schema->resultset('CD')->find( { @@ -436,24 +477,7 @@ Additionally, you can specify the columns explicitly by name: { key => 'cd_artist_title' } ); -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 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. +See also L and L. =cut @@ -461,14 +485,16 @@ sub find { my $self = shift; my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); - # Parse out a query from input - my $input_query; + my $rsrc = $self->result_source; + + # Parse out the condition from input + my $call_cond; if (ref $_[0] eq 'HASH') { - $input_query = { %{$_[0]} }; + $call_cond = { %{$_[0]} }; } else { my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary'; - my @c_cols = $self->result_source->unique_constraint_columns($constraint); + my @c_cols = $rsrc->unique_constraint_columns($constraint); $self->throw_exception( "No constraint columns, maybe a malformed '$constraint' constraint?" @@ -479,22 +505,22 @@ sub find { . "corresponding to the columns of the specified unique constraint '$constraint'" ) unless @c_cols == @_; - $input_query = {}; - @{$input_query}{@c_cols} = @_; + $call_cond = {}; + @{$call_cond}{@c_cols} = @_; } my %related; - for my $key (keys %$input_query) { + for my $key (keys %$call_cond) { if ( - my $keyref = ref($input_query->{$key}) + my $keyref = ref($call_cond->{$key}) and - my $relinfo = $self->result_source->relationship_info($key) + my $relinfo = $rsrc->relationship_info($key) ) { - my $val = delete $input_query->{$key}; + my $val = delete $call_cond->{$key}; next if $keyref eq 'ARRAY'; # has_many for multi_create - my $rel_q = $self->result_source->_resolve_condition( + my $rel_q = $rsrc->_resolve_condition( $relinfo->{cond}, $val, $key ); die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH'; @@ -503,17 +529,20 @@ sub find { } # relationship conditions take precedence (?) - @{$input_query}{keys %related} = values %related; + @{$call_cond}{keys %related} = values %related; - # 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; + my $final_cond; 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); + $final_cond = $self->_qualify_cond_columns ( + + $self->_build_unique_cond ( + $attrs->{key}, + $call_cond, + ), + + $alias, + ); } elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') { # This means that we got here after a merger of relationship conditions @@ -524,18 +553,28 @@ sub find { # relationship } else { - # no key was specified - fall down to heuristics mode - # get all possible unique queries based on the combination of $query - # and the condition available in $self, and then run a search with - # each and every possible constraint (as long as it's completely specified) - 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); + # no key was specified - fall down to heuristics mode: + # run through all unique queries registered on the resultset, and + # 'OR' all qualifying queries together + my (@unique_queries, %seen_column_combinations); + for my $c_name ($rsrc->unique_constraint_names) { + next if $seen_column_combinations{ + join "\x00", sort $rsrc->unique_constraint_columns($c_name) + }++; + + push @unique_queries, try { + $self->_build_unique_cond ($c_name, $call_cond) + } || (); + } + + $final_cond = @unique_queries + ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ] + : $self->_non_unique_find_fallback ($call_cond, $attrs) + ; } # Run the query, passing the result_class since it should propagate for find - my $rs = $self->search ($query, {result_class => $self->result_class, %$attrs}); + my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs}); if (keys %{$rs->_resolved_attrs->{collapse}}) { my $row = $rs->next; carp "Query returned more than one row" if $rs->next; @@ -546,71 +585,65 @@ sub find { } } -# _add_alias +# This is a stop-gap method as agreed during the discussion on find() cleanup: +# http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html +# +# It is invoked when find() is called in legacy-mode with insufficiently-unique +# condition. It is provided for overrides until a saner way forward is devised +# +# *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down +# the road. Please adjust your tests accordingly to catch this situation early +# DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable # -# Add the specified alias to the specified query hash. A copy is made so the -# original query is not modified. +# The method will not be removed without an adequately complete replacement +# for strict-mode enforcement +sub _non_unique_find_fallback { + my ($self, $cond, $attrs) = @_; + + return $self->_qualify_cond_columns( + $cond, + exists $attrs->{alias} + ? $attrs->{alias} + : $self->{attrs}{alias} + ); +} -sub _add_alias { - my ($self, $query, $alias) = @_; - my %aliased = %$query; - foreach my $col (grep { ! m/\./ } keys %aliased) { - $aliased{"$alias.$col"} = delete $aliased{$col}; +sub _qualify_cond_columns { + my ($self, $cond, $alias) = @_; + + my %aliased = %$cond; + for (keys %aliased) { + $aliased{"$alias.$_"} = delete $aliased{$_} + if $_ !~ /\./; } return \%aliased; } -# _unique_queries -# -# Build a list of queries which satisfy the unique constraint(s) as per $attrs - -sub _unique_queries { - my ($self, $query, $attrs) = @_; - - my @constraint_names = exists $attrs->{key} - ? ($attrs->{key}) - : $self->result_source->unique_constraint_names; - - my $where = $self->_collapse_cond($self->{attrs}{where} || {}); - my $num_where = scalar keys %$where; - - my (@unique_queries, %seen_column_combinations); - foreach my $name (@constraint_names) { - my @constraint_cols = $self->result_source->unique_constraint_columns($name); +sub _build_unique_cond { + my ($self, $constraint_name, $extra_cond) = @_; - my $constraint_sig = join "\x00", sort @constraint_cols; - next if $seen_column_combinations{$constraint_sig}++; + my @c_cols = $self->result_source->unique_constraint_columns($constraint_name); - my $unique_query = $self->_build_unique_query($query, \@constraint_cols); + # combination may fail if $self->{cond} is non-trivial + my ($final_cond) = try { + $self->_merge_with_rscond ($extra_cond) + } catch { + +{ %$extra_cond } + }; - my $num_cols = scalar @constraint_cols; - my $num_query = scalar keys %$unique_query; + # trim out everything not in $columns + $final_cond = { map { $_ => $final_cond->{$_} } @c_cols }; - my $total = $num_query + $num_where; - if ($num_query && ($num_query == $num_cols || $total == $num_cols)) { - # The query is either unique on its own or is unique in combination with - # the existing where clause - push @unique_queries, $unique_query; - } + if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) { + $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s", + $constraint_name, + join (', ', map { "'$_'" } @missing), + ) ); } - return @unique_queries; -} - -# _build_unique_query -# -# Constrain the specified query hash based on the specified column names. - -sub _build_unique_query { - my ($self, $query, $unique_cols) = @_; - - return { - map { $_ => $query->{$_} } - grep { exists $query->{$_} } - @$unique_cols - }; + return $final_cond; } =head2 search_related @@ -1699,7 +1732,7 @@ sub populate { } ## inherit the data locked in the conditions of the resultset - my ($rs_data) = $self->_merge_cond_with_data({}); + my ($rs_data) = $self->_merge_with_rscond({}); delete @{$rs_data}{@columns}; my @inherit_cols = keys %$rs_data; my @inherit_data = values %$rs_data; @@ -1839,7 +1872,8 @@ my $mk_lazy_count_wizard = sub { # the tie class for 5.8.1 { - package DBIx::Class::__DBIC_LAZY_RS_COUNT__; + package # hide from pause + DBIx::Class::__DBIC_LAZY_RS_COUNT__; use base qw/Tie::Hash/; sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} } @@ -2006,7 +2040,7 @@ sub new_result { $self->throw_exception( "new_result needs a hash" ) unless (ref $values eq 'HASH'); - my ($merged_cond, $cols_from_relations) = $self->_merge_cond_with_data($values); + my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values); my %new = ( %$merged_cond, @@ -2020,13 +2054,13 @@ sub new_result { return $self->result_class->new(\%new); } -# _merge_cond_with_data +# _merge_with_rscond # # Takes a simple hash of K/V data and returns its copy merged with the # condition already present on the resultset. Additionally returns an # arrayref of value/condition names, which were inferred from related # objects (this is needed for in-memory related objects) -sub _merge_cond_with_data { +sub _merge_with_rscond { my ($self, $data) = @_; my (%new_data, @cols_from_relations); @@ -2227,17 +2261,18 @@ sub as_query { $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. +Find an existing record from this resultset using L. 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. +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. +If you want objects to be saved immediately, use L instead. + +B: Make sure to read the documentation of L and understand the +significance of the C attribute, as its lack may skew your search, and +subsequently result in spurious new objects. B: Take care when using C with a table having columns with default values that you intend to be automatically @@ -2379,6 +2414,10 @@ constraint. For example: { key => 'cd_artist_title' } ); +B: Make sure to read the documentation of L and understand the +significance of the C attribute, as its lack may skew your search, and +subsequently result in spurious row creation. + 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 @@ -2412,16 +2451,15 @@ sub find_or_create { =item Arguments: \%col_values, { key => $unique_constraint }? -=item Return Value: $rowobject +=item Return Value: $row_object =back $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 -found, updates it with the other given column values. Otherwise, creates a new -row. +Like L, but if a row is found it is immediately updated via +C<< $found_row->update (\%col_values) >>. + Takes an optional C attribute to search on a specific unique constraint. For example: @@ -2443,14 +2481,9 @@ For example: key => 'primary', }); - -If no C is specified, it searches on all unique constraints defined on the -source, including the primary key. - -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: Make sure to read the documentation of L and understand the +significance of the C attribute, as its lack may skew your search, and +subsequently result in spurious row creation. B: Take care when using C with a table having columns with default values that you intend to be automatically @@ -2458,6 +2491,9 @@ supplied by the database (e.g. an auto_increment primary key column). In normal usage, the value of such columns should NOT be included at all in the call to C, even when set to C. +See also L and L. For information on how to declare +unique constraints, see L. + =cut sub update_or_create { @@ -2486,13 +2522,9 @@ sub update_or_create { $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. +Like L but if a row is found it is immediately updated via +C<< $found_row->update (\%col_values) >>. -Takes an optional C attribute to search on a specific unique constraint. For example: # In your application @@ -2513,13 +2545,17 @@ For example: $cd->insert; } +B: Make sure to read the documentation of L and understand the +significance of the C attribute, as its lack may skew your search, and +subsequently result in spurious new objects. + B: Take care when using C with a table having columns with default values that you intend to be automatically supplied by the database (e.g. an auto_increment primary key column). In normal usage, the value of such columns should NOT be included at all in the call to C, even when set to C. -See also L, L and L. +See also L, L and L. =cut @@ -3096,34 +3132,9 @@ sub _resolved_attrs { carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)"); } else { - my $storage = $self->result_source->schema->storage; - my $rs_column_list = $storage->_resolve_column_info ($attrs->{from}); - - my $group_spec = $attrs->{group_by} = []; - my %group_index; - - for (@{$attrs->{select}}) { - if (! ref($_) or ref ($_) ne 'HASH' ) { - push @$group_spec, $_; - $group_index{$_}++; - if ($rs_column_list->{$_} and $_ !~ /\./ ) { - # add a fully qualified version as well - $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++; - } - } - } - # add any order_by parts that are not already present in the group_by - # we need to be careful not to add any named functions/aggregates - # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ] - for my $chunk ($storage->_extract_order_columns($attrs->{order_by})) { - - # only consider real columns (for functions the user got to do an explicit group_by) - my $colinfo = $rs_column_list->{$chunk} - or next; - - $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./; - push @$group_spec, $chunk unless $group_index{$chunk}++; - } + $attrs->{group_by} = $source->storage->_group_over_selection ( + @{$attrs}{qw/from select order_by/} + ); } }