use strict;
use warnings;
+use base qw/DBIx::Class/;
+
use DBIx::Class::ResultSet;
use DBIx::Class::ResultSourceHandle;
-use Carp::Clan qw/^DBIx::Class/;
-use Storable;
-use base qw/DBIx::Class/;
+use DBIx::Class::Exception;
+use Carp::Clan qw/^DBIx::Class/;
__PACKAGE__->mk_group_accessors('simple' => qw/_ordered_columns
_columns _primaries _unique_constraints name resultset_attributes
=head1 SYNOPSIS
+ # Create a table based result source, in a result class.
+
+ package MyDB::Schema::Result::Artist;
+ use base qw/DBIx::Class::Core/;
+
+ __PACKAGE__->table('artist');
+ __PACKAGE__->add_columns(qw/ artistid name /);
+ __PACKAGE__->set_primary_key('artistid');
+ __PACKAGE__->has_many(cds => 'MyDB::Schema::Result::CD');
+
+ 1;
+
+ # Create a query (view) based result source, in a result class
+ package MyDB::Schema::Result::Year2000CDs;
+ use base qw/DBIx::Class::Core/;
+
+ __PACKAGE__->load_components('InflateColumn::DateTime');
+ __PACKAGE__->table_class('DBIx::Class::ResultSource::View');
+
+ __PACKAGE__->table('year2000cds');
+ __PACKAGE__->result_source_instance->is_virtual(1);
+ __PACKAGE__->result_source_instance->view_definition(
+ "SELECT cdid, artist, title FROM cd WHERE year ='2000'"
+ );
+
+
=head1 DESCRIPTION
-A ResultSource is a component of a schema from which results can be directly
-retrieved, most usually a table (see L<DBIx::Class::ResultSource::Table>)
+A ResultSource is an object that represents a source of data for querying.
+
+This class is a base class for various specialised types of result
+sources, for example L<DBIx::Class::ResultSource::Table>. Table is the
+default result source type, so one is created for you when defining a
+result class as described in the synopsis above.
+
+More specifically, the L<DBIx::Class::Core> base class pulls in the
+L<DBIx::Class::ResultSourceProxy::Table> component, which defines
+the L<table|DBIx::Class::ResultSourceProxy::Table/table> method.
+When called, C<table> creates and stores an instance of
+L<DBIx::Class::ResultSoure::Table>. Luckily, to use tables as result
+sources, you don't need to remember any of this.
+
+Result sources representing select queries, or views, can also be
+created, see L<DBIx::Class::ResultSource::View> for full details.
+
+=head2 Finding result source objects
+
+As mentioned above, a result source instance is created and stored for
+you when you define a L<Result Class|DBIx::Class::Manual::Glossary/Result Class>.
+
+You can retrieve the result source at runtime in the following ways:
+
+=over
+
+=item From a Schema object:
+
+ $schema->source($source_name);
+
+=item From a Row object:
+
+ $row->result_source;
+
+=item From a ResultSet object:
-Basic view support also exists, see L<<DBIx::Class::ResultSource::View>.
+ $rs->result_source;
+
+=back
=head1 METHODS
$source->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);
-Adds columns to the result source. If supplied key => hashref pairs, uses
-the hashref as the column_info for that column. Repeated calls of this
-method will add more columns, not replace them.
+Adds columns to the result source. If supplied colname => hashref
+pairs, uses the hashref as the L</column_info> for that column. Repeated
+calls of this method will add more columns, not replace them.
The column names given will be created as accessor methods on your
L<DBIx::Class::Row> objects. You can change the name of the accessor
=item accessor
+ { accessor => '_name' }
+
+ # example use, replace standard accessor with one of your own:
+ sub name {
+ my ($self, $value) = @_;
+
+ die "Name cannot contain digits!" if($value =~ /\d/);
+ $self->_name($value);
+
+ return $self->_name();
+ }
+
Use this to set the name of the accessor method for this column. If unset,
the name of the column will be used.
=item data_type
-This contains the column type. It is automatically filled by the
-L<SQL::Translator::Producer::DBIx::Class::File> producer, and the
-L<DBIx::Class::Schema::Loader> module. If you do not enter a
-data_type, DBIx::Class will attempt to retrieve it from the
-database for you, using L<DBI>'s column_info method. The values of this
-key are typically upper-cased.
+ { data_type => 'integer' }
+
+This contains the column type. It is automatically filled if you use the
+L<SQL::Translator::Producer::DBIx::Class::File> producer, or the
+L<DBIx::Class::Schema::Loader> module.
Currently there is no standard set of values for the data_type. Use
whatever your database supports.
=item size
+ { size => 20 }
+
The length of your column, if it is a column type that can have a size
-restriction. This is currently only used by L<DBIx::Class::Schema/deploy>.
+restriction. This is currently only used to create tables from your
+schema, see L<DBIx::Class::Schema/deploy>.
=item is_nullable
-Set this to a true value for a columns that is allowed to contain
-NULL values. This is currently only used by L<DBIx::Class::Schema/deploy>.
+ { is_nullable => 1 }
+
+Set this to a true value for a columns that is allowed to contain NULL
+values, default is false. This is currently only used to create tables
+from your schema, see L<DBIx::Class::Schema/deploy>.
=item is_auto_increment
+ { is_auto_increment => 1 }
+
Set this to a true value for a column whose value is somehow
-automatically set. This is used to determine which columns to empty
-when cloning objects using C<copy>. It is also used by
+automatically set, defaults to false. This is used to determine which
+columns to empty when cloning objects using
+L<DBIx::Class::Row/copy>. It is also used by
L<DBIx::Class::Schema/deploy>.
+=item is_numeric
+
+ { is_numeric => 1 }
+
+Set this to a true or false value (not C<undef>) to explicitly specify
+if this column contains numeric data. This controls how set_column
+decides whether to consider a column dirty after an update: if
+C<is_numeric> is true a numeric comparison C<< != >> will take place
+instead of the usual C<eq>
+
+If not specified the storage class will attempt to figure this out on
+first access to the column, based on the column C<data_type>. The
+result will be cached in this attribute.
+
=item is_foreign_key
+ { is_foreign_key => 1 }
+
Set this to a true value for a column that contains a key from a
-foreign table. This is currently only used by
-L<DBIx::Class::Schema/deploy>.
+foreign table, defaults to false. This is currently only used to
+create tables from your schema, see L<DBIx::Class::Schema/deploy>.
=item default_value
-Set this to the default value which will be inserted into a column
-by the database. Can contain either a value or a function. This is
-currently only used by L<DBIx::Class::Schema/deploy>.
+ { default_value => \'now()' }
+
+Set this to the default value which will be inserted into a column by
+the database. Can contain either a value or a function (use a
+reference to a scalar e.g. C<\'now()'> if you want a function). This
+is currently only used to create tables from your schema, see
+L<DBIx::Class::Schema/deploy>.
+
+See the note on L<DBIx::Class::Row/new> for more information about possible
+issues related to db-side default values.
=item sequence
+ { sequence => 'my_table_seq' }
+
Set this on a primary key column to the name of the sequence used to
generate a new key value. If not specified, L<DBIx::Class::PK::Auto>
will attempt to retrieve the name of the sequence from the database
=item auto_nextval
-Set this to a true value for a column whose value is retrieved
-automatically from an oracle sequence. If you do not use an Oracle
-trigger to get the nextval, you have to set sequence as well.
+Set this to a true value for a column whose value is retrieved automatically
+from a sequence or function (if supported by your Storage driver.) For a
+sequence, if you do not use a trigger to get the nextval, you have to set the
+L</sequence> value as well.
+
+Also set this for MSSQL columns with the 'uniqueidentifier'
+L<DBIx::Class::ResultSource/data_type> whose values you want to automatically
+generate using C<NEWID()>, unless they are a primary key in which case this will
+be done anyway.
=item extra
=over
-=item Arguments: $colname, [ \%columninfo ]
+=item Arguments: $colname, \%columninfo?
=item Return value: 1/0 (true/false)
=back
- $source->add_column('col' => \%info?);
+ $source->add_column('col' => \%info);
Add a single column and optional column info. Uses the same column
info keys as L</add_columns>.
my $info = $source->column_info($col);
Returns the column metadata hashref for a column, as originally passed
-to L</add_columns>. See the description of L</add_columns> for information
-on the contents of the hashref.
+to L</add_columns>. See L</add_columns> above for information on the
+contents of the hashref.
=cut
my $self = shift;
$self->throw_exception(
"columns() is a read-only accessor, did you mean add_columns()?"
- ) if (@_ > 1);
+ ) if @_;
return @{$self->{_ordered_columns}||[]};
}
=back
-Defines one or more columns as primary key for this source. Should be
+Defines one or more columns as primary key for this source. Must be
called after L</add_columns>.
Additionally, defines a L<unique constraint|add_unique_constraint>
named C<primary>.
The primary key columns are used by L<DBIx::Class::PK::Auto> to
-retrieve automatically created values from the database.
+retrieve automatically created values from the database. They are also
+used as default joining columns when specifying relationships, see
+L<DBIx::Class::Relationship>.
=cut
return @{shift->_primaries||[]};
}
+sub _pri_cols {
+ my $self = shift;
+ my @pcols = $self->primary_columns
+ or $self->throw_exception (sprintf(
+ 'Operation requires a primary key to be declared on %s via set_primary_key',
+ $self->source_name,
+ ));
+ return @pcols;
+}
+
=head2 add_unique_constraint
=over 4
-=item Arguments: [ $name ], \@colnames
+=item Arguments: $name?, \@colnames
=item Return value: undefined
__PACKAGE__->add_unique_constraint([ qw/column1 column2/ ]);
-This will result in a unique constraint named C<table_column1_column2>, where
-C<table> is replaced with the table name.
+This will result in a unique constraint named
+C<table_column1_column2>, where C<table> is replaced with the table
+name.
-Unique constraints are used, for example, when you call
-L<DBIx::Class::ResultSet/find>. Only columns in the constraint are searched.
+Unique constraints are used, for example, when you pass the constraint
+name as the C<key> attribute to L<DBIx::Class::ResultSet/find>. Then
+only columns in the constraint are searched.
Throws an error if any of the given column names do not yet exist on
the result source.
sub name_unique_constraint {
my ($self, $cols) = @_;
- return join '_', $self->name, @$cols;
+ my $name = $self->name;
+ $name = $$name if (ref $name eq 'SCALAR');
+
+ return join '_', $name, @$cols;
}
=head2 unique_constraints
$source->unique_constraints();
-Read-only accessor which returns a hash of unique constraints on this source.
+Read-only accessor which returns a hash of unique constraints on this
+source.
The hash is keyed by constraint name, and contains an arrayref of
column names as values.
=back
- package My::ResultSetClass;
+ package My::Schema::ResultSet::Artist;
use base 'DBIx::Class::ResultSet';
...
- $source->resultset_class('My::ResultSet::Class');
+ # In the result class
+ __PACKAGE__->resultset_class('My::Schema::ResultSet::Artist');
+
+ # Or in code
+ $source->resultset_class('My::Schema::ResultSet::Artist');
Set the class of the resultset. This is useful if you want to create your
own resultset methods. Create your own class derived from
=back
+ # In the result class
+ __PACKAGE__->resultset_attributes({ order_by => [ 'id' ] });
+
+ # Or in code
$source->resultset_attributes({ order_by => [ 'id' ] });
Store a collection of resultset attributes, that will be set on every
=back
Throws an exception if the condition is improperly supplied, or cannot
-be resolved using L</resolve_join>.
+be resolved.
=cut
}
return unless $f_source; # Can't test rel without f_source
- eval { $self->resolve_join($rel, 'me') };
+ eval { $self->_resolve_join($rel, 'me', {}, []) };
if ($@) { # If the resolve failed, back out and re-throw the error
delete $rels{$rel}; #
L<DBIx::Class::Relationship>.
The returned hashref is keyed by the name of the opposing
-relationship, and contains it's data in the same manner as
+relationship, and contains its data in the same manner as
L</relationship_info>.
=cut
my @other_cond = keys(%$othercond);
my @other_refkeys = map {/^\w+\.(\w+)$/} @other_cond;
my @other_keys = map {$othercond->{$_} =~ /^\w+\.(\w+)$/} @other_cond;
- next if (!$self->compare_relationship_keys(\@refkeys, \@other_keys) ||
- !$self->compare_relationship_keys(\@other_refkeys, \@keys));
+ next if (!$self->_compare_relationship_keys(\@refkeys, \@other_keys) ||
+ !$self->_compare_relationship_keys(\@other_refkeys, \@keys));
$ret->{$otherrel} = $otherrel_info;
}
}
return $ret;
}
-=head2 compare_relationship_keys
-
-=over 4
-
-=item Arguments: \@keys1, \@keys2
-
-=item Return value: 1/0 (true/false)
-
-=back
-
-Returns true if both sets of keynames are the same, false otherwise.
-
-=cut
-
sub compare_relationship_keys {
+ carp 'compare_relationship_keys is a private method, stop calling it';
+ my $self = shift;
+ $self->_compare_relationship_keys (@_);
+}
+
+# Returns true if both sets of keynames are the same, false otherwise.
+sub _compare_relationship_keys {
my ($self, $keys1, $keys2) = @_;
# Make sure every keys1 is in keys2
return $found;
}
-=head2 resolve_join
-
-=over 4
+# Returns the {from} structure used to express JOIN conditions
+sub _resolve_join {
+ my ($self, $join, $alias, $seen, $jpath, $parent_force_left) = @_;
-=item Arguments: $relation
+ # we need a supplied one, because we do in-place modifications, no returns
+ $self->throw_exception ('You must supply a seen hashref as the 3rd argument to _resolve_join')
+ unless ref $seen eq 'HASH';
-=item Return value: Join condition arrayref
+ $self->throw_exception ('You must supply a joinpath arrayref as the 4th argument to _resolve_join')
+ unless ref $jpath eq 'ARRAY';
-=back
-
-Returns the join structure required for the related result source.
-
-=cut
+ $jpath = [@$jpath]; # copy
-sub resolve_join {
- my ($self, $join, $alias, $seen, $force_left) = @_;
- $seen ||= {};
- $force_left ||= { force => 0 };
- if (ref $join eq 'ARRAY') {
- return map { $self->resolve_join($_, $alias, $seen) } @$join;
- } elsif (ref $join eq 'HASH') {
+ if (not defined $join) {
+ return ();
+ }
+ elsif (ref $join eq 'ARRAY') {
return
map {
- my $as = ($seen->{$_} ? $_.'_'.($seen->{$_}+1) : $_);
- local $force_left->{force};
- (
- $self->resolve_join($_, $alias, $seen, $force_left),
- $self->related_source($_)->resolve_join(
- $join->{$_}, $as, $seen, $force_left
- )
- );
- } keys %$join;
- } elsif (ref $join) {
- $self->throw_exception("No idea how to resolve join reftype ".ref $join);
- } else {
- my $count = ++$seen->{$join};
- #use Data::Dumper; warn Dumper($seen);
- my $as = ($count > 1 ? "${join}_${count}" : $join);
- my $rel_info = $self->relationship_info($join);
- $self->throw_exception("No such relationship ${join}") unless $rel_info;
- my $type;
- if ($force_left->{force}) {
- $type = 'left';
- } else {
- $type = $rel_info->{attrs}{join_type} || '';
- $force_left->{force} = 1 if lc($type) eq 'left';
- }
- return [ { $as => $self->related_source($join)->from,
- -join_type => $type },
- $self->resolve_condition($rel_info->{cond}, $as, $alias) ];
+ $self->_resolve_join($_, $alias, $seen, $jpath, $parent_force_left);
+ } @$join;
}
-}
+ elsif (ref $join eq 'HASH') {
-=head2 pk_depends_on
+ my @ret;
+ for my $rel (keys %$join) {
-=over 4
+ my $rel_info = $self->relationship_info($rel)
+ or $self->throw_exception("No such relationship ${rel}");
-=item Arguments: $relname, $rel_data
+ my $force_left = $parent_force_left;
+ $force_left ||= lc($rel_info->{attrs}{join_type}||'') eq 'left';
-=item Return value: 1/0 (true/false)
+ # the actual seen value will be incremented by the recursion
+ my $as = $self->storage->relname_to_table_alias(
+ $rel, ($seen->{$rel} && $seen->{$rel} + 1)
+ );
-=back
-
-Determines whether a relation is dependent on an object from this source
-having already been inserted. Takes the name of the relationship and a
-hashref of columns of the related object.
+ push @ret, (
+ $self->_resolve_join($rel, $alias, $seen, [@$jpath], $force_left),
+ $self->related_source($rel)->_resolve_join(
+ $join->{$rel}, $as, $seen, [@$jpath, { $rel => $as }], $force_left
+ )
+ );
+ }
+ return @ret;
-=cut
+ }
+ elsif (ref $join) {
+ $self->throw_exception("No idea how to resolve join reftype ".ref $join);
+ }
+ else {
+ my $count = ++$seen->{$join};
+ my $as = $self->storage->relname_to_table_alias(
+ $join, ($count > 1 && $count)
+ );
+
+ my $rel_info = $self->relationship_info($join)
+ or $self->throw_exception("No such relationship ${join}");
+
+ my $rel_src = $self->related_source($join);
+ return [ { $as => $rel_src->from,
+ -source_handle => $rel_src->handle,
+ -join_type => $parent_force_left
+ ? 'left'
+ : $rel_info->{attrs}{join_type}
+ ,
+ -join_path => [@$jpath, { $join => $as } ],
+ -is_single => (
+ $rel_info->{attrs}{accessor}
+ &&
+ List::Util::first { $rel_info->{attrs}{accessor} eq $_ } (qw/single filter/)
+ ),
+ -alias => $as,
+ -relation_chain_depth => $seen->{-relation_chain_depth} || 0,
+ },
+ $self->_resolve_condition($rel_info->{cond}, $as, $alias) ];
+ }
+}
sub pk_depends_on {
+ carp 'pk_depends_on is a private method, stop calling it';
+ my $self = shift;
+ $self->_pk_depends_on (@_);
+}
+
+# Determines whether a relation is dependent on an object from this source
+# having already been inserted. Takes the name of the relationship and a
+# hashref of columns of the related object.
+sub _pk_depends_on {
my ($self, $relname, $rel_data) = @_;
- my $cond = $self->relationship_info($relname)->{cond};
+ my $relinfo = $self->relationship_info($relname);
+
+ # don't assume things if the relationship direction is specified
+ return $relinfo->{attrs}{is_foreign_key_constraint}
+ if exists ($relinfo->{attrs}{is_foreign_key_constraint});
+
+ my $cond = $relinfo->{cond};
return 0 unless ref($cond) eq 'HASH';
# map { foreign.foo => 'self.bar' } to { bar => 'foo' }
-
my $keyhash = { map { my $x = $_; $x =~ s/.*\.//; $x; } reverse %$cond };
# assume anything that references our PK probably is dependent on us
# rather than vice versa, unless the far side is (a) defined or (b)
# auto-increment
-
my $rel_source = $self->related_source($relname);
foreach my $p ($self->primary_columns) {
return 1;
}
-=head2 resolve_condition
-
-=over 4
-
-=item Arguments: $cond, $as, $alias|$object
-
-=back
-
-Resolves the passed condition to a concrete query fragment. If given an alias,
-returns a join condition; if given an object, inverts that object to produce
-a related conditional from that object.
-
-=cut
+sub resolve_condition {
+ carp 'resolve_condition is a private method, stop calling it';
+ my $self = shift;
+ $self->_resolve_condition (@_);
+}
-our $UNRESOLVABLE_CONDITION = \'1 = 0';
+# Resolves the passed condition to a concrete query fragment. If given an alias,
+# returns a join condition; if given an object, inverts that object to produce
+# a related conditional from that object.
+our $UNRESOLVABLE_CONDITION = \ '1 = 0';
-sub resolve_condition {
+sub _resolve_condition {
my ($self, $cond, $as, $for) = @_;
- #warn %$cond;
if (ref $cond eq 'HASH') {
my %ret;
foreach my $k (keys %{$cond}) {
#warn "$self $k $for $v";
unless ($for->has_column_loaded($v)) {
if ($for->in_storage) {
- $self->throw_exception("Column ${v} not loaded on ${for} trying to resolve relationship");
+ $self->throw_exception(sprintf
+ "Unable to resolve relationship '%s' from object %s: column '%s' not "
+ . 'loaded from storage (or not passed to new() prior to insert()). You '
+ . 'probably need to call ->discard_changes to get the server-side defaults '
+ . 'from the database.',
+ $as,
+ $for,
+ $v,
+ );
}
return $UNRESOLVABLE_CONDITION;
}
}
return \%ret;
} elsif (ref $cond eq 'ARRAY') {
- return [ map { $self->resolve_condition($_, $as, $for) } @$cond ];
+ return [ map { $self->_resolve_condition($_, $as, $for) } @$cond ];
} else {
- die("Can't handle this yet :(");
+ die("Can't handle condition $cond yet :(");
}
}
-=head2 resolve_prefetch
-
-=over 4
-=item Arguments: hashref/arrayref/scalar
+# Accepts one or more relationships for the current source and returns an
+# array of column names for each of those relationships. Column names are
+# prefixed relative to the current source, in accordance with where they appear
+# in the supplied relationships.
-=back
-
-Accepts one or more relationships for the current source and returns an
-array of column names for each of those relationships. Column names are
-prefixed relative to the current source, in accordance with where they appear
-in the supplied relationships. Examples:
-
- my $source = $schema->resultset('Tag')->source;
- @columns = $source->resolve_prefetch( { cd => 'artist' } );
-
- # @columns =
- #(
- # 'cd.cdid',
- # 'cd.artist',
- # 'cd.title',
- # 'cd.year',
- # 'cd.artist.artistid',
- # 'cd.artist.name'
- #)
-
- @columns = $source->resolve_prefetch( qw[/ cd /] );
-
- # @columns =
- #(
- # 'cd.cdid',
- # 'cd.artist',
- # 'cd.title',
- # 'cd.year'
- #)
-
- $source = $schema->resultset('CD')->source;
- @columns = $source->resolve_prefetch( qw[/ artist producer /] );
-
- # @columns =
- #(
- # 'artist.artistid',
- # 'artist.name',
- # 'producer.producerid',
- # 'producer.name'
- #)
-
-=cut
+sub _resolve_prefetch {
+ my ($self, $pre, $alias, $alias_map, $order, $pref_path) = @_;
+ $pref_path ||= [];
-sub resolve_prefetch {
- my ($self, $pre, $alias, $seen, $order, $collapse) = @_;
- $seen ||= {};
- #$alias ||= $self->name;
- #warn $alias, Dumper $pre;
- if( ref $pre eq 'ARRAY' ) {
+ if (not defined $pre) {
+ return ();
+ }
+ elsif( ref $pre eq 'ARRAY' ) {
return
- map { $self->resolve_prefetch( $_, $alias, $seen, $order, $collapse ) }
+ map { $self->_resolve_prefetch( $_, $alias, $alias_map, $order, [ @$pref_path ] ) }
@$pre;
}
elsif( ref $pre eq 'HASH' ) {
my @ret =
map {
- $self->resolve_prefetch($_, $alias, $seen, $order, $collapse),
- $self->related_source($_)->resolve_prefetch(
- $pre->{$_}, "${alias}.$_", $seen, $order, $collapse)
+ $self->_resolve_prefetch($_, $alias, $alias_map, $order, [ @$pref_path ] ),
+ $self->related_source($_)->_resolve_prefetch(
+ $pre->{$_}, "${alias}.$_", $alias_map, $order, [ @$pref_path, $_] )
} keys %$pre;
- #die Dumper \@ret;
return @ret;
}
elsif( ref $pre ) {
"don't know how to resolve prefetch reftype ".ref($pre));
}
else {
- my $count = ++$seen->{$pre};
- my $as = ($count > 1 ? "${pre}_${count}" : $pre);
+ my $p = $alias_map;
+ $p = $p->{$_} for (@$pref_path, $pre);
+
+ $self->throw_exception (
+ "Unable to resolve prefetch '$pre' - join alias map does not contain an entry for path: "
+ . join (' -> ', @$pref_path, $pre)
+ ) if (ref $p->{-join_aliases} ne 'ARRAY' or not @{$p->{-join_aliases}} );
+
+ my $as = shift @{$p->{-join_aliases}};
+
my $rel_info = $self->relationship_info( $pre );
$self->throw_exception( $self->name . " has no such relationship '$pre'" )
unless $rel_info;
my $as_prefix = ($alias =~ /^.*?\.(.+)$/ ? $1.'.' : '');
my $rel_source = $self->related_source($pre);
- if (exists $rel_info->{attrs}{accessor}
- && $rel_info->{attrs}{accessor} eq 'multi') {
+ if ($rel_info->{attrs}{accessor} && $rel_info->{attrs}{accessor} eq 'multi') {
$self->throw_exception(
"Can't prefetch has_many ${pre} (join cond too complex)")
unless ref($rel_info->{cond}) eq 'HASH';
my $dots = @{[$as_prefix =~ m/\./g]} + 1; # +1 to match the ".${as_prefix}"
- if (my ($fail) = grep { @{[$_ =~ m/\./g]} == $dots }
- keys %{$collapse}) {
- my ($last) = ($fail =~ /([^\.]+)$/);
- carp (
- "Prefetching multiple has_many rels ${last} and ${pre} "
- .(length($as_prefix)
- ? "at the same level (${as_prefix}) "
- : "at top level "
- )
- . 'will currently disrupt both the functionality of $rs->count(), '
- . 'and the amount of objects retrievable via $rs->next(). '
- . 'Use at your own risk.'
- );
- }
+
#my @col = map { (/^self\.(.+)$/ ? ("${as_prefix}.$1") : ()); }
# values %{$rel_info->{cond}};
- $collapse->{".${as_prefix}${pre}"} = [ $rel_source->primary_columns ];
- # action at a distance. prepending the '.' allows simpler code
- # in ResultSet->_collapse_result
my @key = map { (/^foreign\.(.+)$/ ? ($1) : ()); }
keys %{$rel_info->{cond}};
my @ord = (ref($rel_info->{attrs}{order_by}) eq 'ARRAY'
? @{$rel_info->{attrs}{order_by}}
- : (defined $rel_info->{attrs}{order_by}
+
+ : (defined $rel_info->{attrs}{order_by}
? ($rel_info->{attrs}{order_by})
- : ()));
+ : ()
+ ));
push(@$order, map { "${as}.$_" } (@key, @ord));
}
return map { [ "${as}.$_", "${as_prefix}${pre}.$_", ] }
$rel_source->columns;
- #warn $alias, Dumper (\@ret);
- #return @ret;
+ }
+}
+
+# Takes a selection list and generates a collapse-map representing
+# row-object fold-points. Every relationship is assigned a set of unique,
+# non-nullable columns (which may *not even be* from the same resultset)
+# and the collapser will use this information to correctly distinguish
+# data of individual to-be-row-objects.
+sub _resolve_collapse {
+ my ($self, $as, $as_fq_idx, $rel_chain, $parent_info) = @_;
+
+ # for comprehensible error messages put ourselves at the head of the relationship chain
+ $rel_chain ||= [ $self->source_name ];
+
+ # record top-level fully-qualified column index
+ $as_fq_idx ||= { %$as };
+
+ my ($my_cols, $rel_cols);
+ for (keys %$as) {
+ if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
+ $rel_cols->{$1}{$2} = 1;
+ }
+ else {
+ $my_cols->{$_} = {}; # important for ||= below
+ }
+ }
+
+ my $relinfo;
+ # run through relationships, collect metadata, inject non-left fk-bridges from
+ # *INNER-JOINED* children (if any)
+ for my $rel (keys %$rel_cols) {
+ my $rel_src = $self->related_source ($rel);
+ my $inf = $self->relationship_info ($rel);
+
+ $relinfo->{$rel}{is_single} = $inf->{attrs}{accessor} && $inf->{attrs}{accessor} ne 'multi';
+ $relinfo->{$rel}{is_inner} = ( $inf->{attrs}{join_type} || '' ) !~ /^left/i;
+ $relinfo->{$rel}{rsrc} = $rel_src;
+
+ my $cond = $inf->{cond};
+
+ if (
+ ref $cond eq 'HASH'
+ and
+ keys %$cond
+ and
+ ! List::Util::first { $_ !~ /^foreign\./ } (keys %$cond)
+ and
+ ! List::Util::first { $_ !~ /^self\./ } (values %$cond)
+ ) {
+ for my $f (keys %$cond) {
+ my $s = $cond->{$f};
+ $_ =~ s/^ (?: foreign | self ) \.//x for ($f, $s);
+ $relinfo->{$rel}{fk_map}{$s} = $f;
+
+ $my_cols->{$s} ||= { via_fk => "$rel.$f" } # need to know source from *our* pov
+ if ($relinfo->{$rel}{is_inner} && defined $rel_cols->{$rel}{$f}); # only if it is inner and in fact selected of course
+ }
+ }
+ }
+
+ # if the parent is already defined, assume all of its related FKs are selected
+ # (even if they in fact are NOT in the select list). Keep a record of what we
+ # assumed, and if any such phantom-column becomes part of our own collapser,
+ # throw everything assumed-from-parent away and replace with the collapser of
+ # the parent (whatever it may be)
+ my $assumed_from_parent;
+ unless ($parent_info->{underdefined}) {
+ $assumed_from_parent->{columns} = { map
+ # only add to the list if we do not already select said columns
+ { ! exists $my_cols->{$_} ? ( $_ => 1 ) : () }
+ values %{$parent_info->{rel_condition} || {}}
+ };
+
+ $my_cols->{$_} = { via_collapse => $parent_info->{collapse_on} }
+ for keys %{$assumed_from_parent->{columns}};
+ }
+
+ # get colinfo for everything
+ if ($my_cols) {
+ $my_cols->{$_}{colinfo} = (
+ $self->has_column ($_) ? $self->column_info ($_) : undef
+ ) for keys %$my_cols;
+ }
+
+ my $collapse_map;
+
+ # try to resolve based on our columns (plus already inserted FK bridges)
+ if (
+ $my_cols
+ and
+ my $uset = $self->_unique_column_set ($my_cols)
+ ) {
+ # see if the resulting collapser relies on any implied columns,
+ # and fix stuff up if this is the case
+
+ my $parent_collapser_used;
+
+ if (List::Util::first
+ { exists $assumed_from_parent->{columns}{$_} }
+ keys %$uset
+ ) {
+ # remove implied stuff from the uset, we will inject the equivalent collapser a bit below
+ delete @{$uset}{keys %{$assumed_from_parent->{columns}}};
+ $parent_collapser_used = 1;
+ }
+
+ $collapse_map->{-collapse_on} = {
+ %{ $parent_collapser_used ? $parent_info->{collapse_on} : {} },
+ (map
+ {
+ my $fqc = join ('.',
+ @{$rel_chain}[1 .. $#$rel_chain],
+ ( $my_cols->{$_}{via_fk} || $_ ),
+ );
+
+ $fqc => $as_fq_idx->{$fqc};
+ }
+ keys %$uset
+ ),
+ };
+ }
+
+ # don't know how to collapse - keep descending down 1:1 chains - if
+ # a related non-LEFT 1:1 is resolvable - its condition will collapse us
+ # too
+ unless ($collapse_map->{-collapse_on}) {
+ my @candidates;
+
+ for my $rel (keys %$relinfo) {
+ next unless ($relinfo->{$rel}{is_single} && $relinfo->{$rel}{is_inner});
+
+ if ( my $rel_collapse = $relinfo->{$rel}{rsrc}->_resolve_collapse (
+ $rel_cols->{$rel},
+ $as_fq_idx,
+ [ @$rel_chain, $rel ],
+ { underdefined => 1 }
+ )) {
+ push @candidates, $rel_collapse->{-collapse_on};
+ }
+ }
+
+ # get the set with least amount of columns
+ # FIXME - maybe need to implement a data type order as well (i.e. prefer several ints
+ # to a single varchar)
+ if (@candidates) {
+ ($collapse_map->{-collapse_on}) = sort { keys %$a <=> keys %$b } (@candidates);
+ }
+ }
+
+ # Still dont know how to collapse - see if the parent passed us anything
+ # (i.e. reuse collapser over 1:1)
+ unless ($collapse_map->{-collapse_on}) {
+ $collapse_map->{-collapse_on} = $parent_info->{collapse_on}
+ if $parent_info->{collapser_reusable};
+ }
+
+
+ # stop descending into children if we were called by a parent for first-pass
+ # and don't despair if nothing was found (there may be other parallel branches
+ # to dive into)
+ if ($parent_info->{underdefined}) {
+ return $collapse_map->{-collapse_on} ? $collapse_map : undef
+ }
+ # nothing down the chain resolved - can't calculate a collapse-map
+ elsif (! $collapse_map->{-collapse_on}) {
+ $self->throw_exception ( sprintf
+ "Unable to calculate a definitive collapse column set for %s%s: fetch more unique non-nullable columns",
+ $self->source_name,
+ @$rel_chain > 1
+ ? sprintf (' (last member of the %s chain)', join ' -> ', @$rel_chain )
+ : ''
+ ,
+ );
+ }
+
+
+ # If we got that far - we are collapsable - GREAT! Now go down all children
+ # a second time, and fill in the rest
+
+ for my $rel (keys %$relinfo) {
+
+ $collapse_map->{$rel} = $relinfo->{$rel}{rsrc}->_resolve_collapse (
+ { map { $_ => 1 } ( keys %{$rel_cols->{$rel}} ) },
+
+ $as_fq_idx,
+
+ [ @$rel_chain, $rel],
+
+ {
+ collapse_on => { %{$collapse_map->{-collapse_on}} },
+
+ rel_condition => $relinfo->{$rel}{fk_map},
+
+ # if this is a 1:1 our own collapser can be used as a collapse-map
+ # (regardless of left or not)
+ collapser_reusable => $relinfo->{$rel}{is_single},
+ },
+ );
+ }
+
+ return $collapse_map;
+}
+
+sub _unique_column_set {
+ my ($self, $cols) = @_;
+
+ my %unique = $self->unique_constraints;
+
+ # always prefer the PK first, and then shortest constraints first
+ USET:
+ for my $set (delete $unique{primary}, sort { @$a <=> @$b } (values %unique) ) {
+ next unless $set && @$set;
+
+ for (@$set) {
+ next USET unless ($cols->{$_} && $cols->{$_}{colinfo} && !$cols->{$_}{colinfo}{is_nullable} );
+ }
+
+ return { map { $_ => 1 } @$set };
+ }
+
+ return undef;
+}
+
+# Takes an arrayref of {as} dbic column aliases and the collapse and select
+# attributes from the same $rs (the slector requirement is a temporary
+# workaround), and returns a coderef capable of:
+# my $me_pref_clps = $coderef->([$rs->cursor->next])
+# Where the $me_pref_clps arrayref is the future argument to
+# ::ResultSet::_collapse_result.
+#
+# $me_pref_clps->[0] is always returned (even if as an empty hash with no
+# rowdata), however branches of related data in $me_pref_clps->[1] may be
+# pruned short of what was originally requested based on {as}, depending
+# on:
+#
+# * If collapse is requested, a definitive collapse map is calculated for
+# every relationship "fold-point", consisting of a set of values (which
+# may not even be contained in the future 'me' of said relationship
+# (for example a cd.artist_id defines the related inner-joined artist)).
+# Thus a definedness check is carried on all collapse-condition values
+# and if at least one is undef it is assumed that we are dealing with a
+# NULLed right-side of a left-join, so we don't return a related data
+# container at all, which implies no related objects
+#
+# * If we are not collapsing, there is no constraint on having a selector
+# uniquely identifying all possible objects, and the user might have very
+# well requested a column that just *happens* to be all NULLs. What we do
+# in this case is fallback to the old behavior (which is a potential FIXME)
+# by always returning a data container, but only filling it with columns
+# IFF at least one of them is defined. This way we do not get an object
+# with a bunch of has_column_loaded to undef, but at the same time do not
+# further relationships based off this "null" object (e.g. in case the user
+# deliberately skipped link-table values). I am pretty sure there are some
+# tests that codify this behavior, need to find the exact testname.
+#
+# For an example of this coderef in action (and to see its guts) look at
+# t/prefetch/_internals.t
+#
+# This is a huge performance win, as we call the same code for
+# every row returned from the db, thus avoiding repeated method
+# lookups when traversing relationships
+#
+# Also since the coderef is completely stateless (the returned structure is
+# always fresh on every new invocation) this is a very good opportunity for
+# memoization if further speed improvements are needed
+#
+# The way we construct this coderef is somewhat fugly, although I am not
+# sure if the string eval is *that* bad of an idea. The alternative is to
+# have a *very* large number of anon coderefs calling each other in a twisty
+# maze, whereas the current result is a nice, smooth, single-pass function.
+# In any case - the output of this thing is meticulously micro-tested, so
+# any sort of rewrite should be relatively easy
+#
+sub _mk_row_parser {
+ my ($self, $as, $with_collapse, $select) = @_;
+
+ my $as_indexed = { map
+ { $as->[$_] => $_ }
+ ( 0 .. $#$as )
+ };
+
+ # calculate collapse fold-points if needed
+ my $collapse_on = do {
+ # FIXME
+ # only consider real columns (not functions) during collapse resolution
+ # this check shouldn't really be here, as fucktards are not supposed to
+ # alias random crap to existing column names anyway, but still - just in
+ # case (also saves us from select/as mismatches which need fixing as well...)
+
+ my $plain_as = { %$as_indexed };
+ for (keys %$plain_as) {
+ delete $plain_as->{$_} if ref $select->[$plain_as->{$_}];
+ }
+ $self->_resolve_collapse ($plain_as);
+
+ } if $with_collapse;
+
+ my $perl = $self->__visit_as ($as_indexed, $collapse_on);
+ my $cref = eval "sub { $perl }"
+ or die "Oops! _mk_row_parser generated invalid perl:\n$@\n\n$perl\n";
+ return $cref;
+}
+
+{
+ my $visit_as_dumper; # keep our own DD object around so we don't have to fitz with quoting
+
+ sub __visit_as {
+ my ($self, $as, $collapse_on, $known_defined) = @_;
+ $known_defined ||= {};
+
+ # prepopulate the known defined map with our own collapse value positions
+ # the rationale is that if an Artist needs column 0 to be uniquely
+ # identified, and related CDs need columns 0 and 1, by the time we get to
+ # CDs we already know that column 0 is defined (otherwise there would be
+ # no related CDs as there is no Artist in the 1st place). So we use this
+ # index to cut on repetitive defined() checks.
+ $known_defined->{$_}++ for ( values %{$collapse_on->{-collapse_on} || {}} );
+
+ my $my_cols = {};
+ my $rel_cols;
+ for (keys %$as) {
+ if ($_ =~ /^ ([^\.]+) \. (.+) /x) {
+ $rel_cols->{$1}{$2} = $as->{$_};
+ }
+ else {
+ $my_cols->{$_} = $as->{$_};
+ }
+ }
+
+ my @relperl;
+ for my $rel (sort keys %$rel_cols) {
+ my $rel_node = $self->__visit_as($rel_cols->{$rel}, $collapse_on->{$rel}, {%$known_defined} );
+
+ my @null_checks;
+ if ($collapse_on->{$rel}{-collapse_on}) {
+ @null_checks = map
+ { "(! defined '__VALPOS__${_}__')" }
+ ( grep
+ { ! $known_defined->{$_} }
+ ( sort
+ { $a <=> $b }
+ values %{$collapse_on->{$rel}{-collapse_on}}
+ )
+ )
+ ;
+ }
+
+ if (@null_checks) {
+ push @relperl, sprintf ( '(%s) ? () : ( %s => %s )',
+ join (' || ', @null_checks ),
+ $rel,
+ $rel_node,
+ );
+ }
+ else {
+ push @relperl, "$rel => $rel_node";
+ }
+ }
+ my $rels = @relperl
+ ? sprintf ('{ %s }', join (',', @relperl))
+ : 'undef'
+ ;
+
+ my $me = {
+ map { $_ => "__VALPOS__$my_cols->{$_}__" } (keys %$my_cols)
+ };
+
+ my $clps = undef; # funny thing, but this prevents a memory leak, I guess it's Data::Dumper#s fault (mo)
+ $clps = [
+ map { "__VALPOS__${_}__" } ( sort { $a <=> $b } (values %{$collapse_on->{-collapse_on}}) )
+ ] if $collapse_on->{-collapse_on};
+
+ # we actually will be producing functional perl code here,
+ # thus no second-guessing of what these globals might have
+ # been set to. DO NOT CHANGE!
+ $visit_as_dumper ||= do {
+ require Data::Dumper;
+ Data::Dumper->new([])
+ ->Purity (1)
+ ->Pad ('')
+ ->Useqq (0)
+ ->Terse (1)
+ ->Quotekeys (1)
+ ->Deepcopy (1)
+ ->Deparse (0)
+ ->Maxdepth (0)
+ ->Indent (0)
+ };
+ for ($me, $clps) {
+ $_ = $visit_as_dumper->Values ([$_])->Dump;
+ }
+
+ unless ($collapse_on->{-collapse_on}) { # we are not collapsing, insert a definedness check on 'me'
+ $me = sprintf ( '(%s) ? %s : {}',
+ join (' || ', map { "( defined '__VALPOS__${_}__')" } (sort { $a <=> $b } values %$my_cols) ),
+ $me,
+ );
+ }
+
+ my @rv_list = ($me, $rels, $clps);
+ pop @rv_list while ($rv_list[-1] eq 'undef'); # strip trailing undefs
+
+ # change the quoted placeholders to unquoted alias-references
+ $_ =~ s/ \' __VALPOS__(\d+)__ \' /sprintf ('$_[0][%d]', $1)/gex
+ for grep { defined $_ } @rv_list;
+ return sprintf '[%s]', join (',', @rv_list);
}
}
sub related_source {
my ($self, $rel) = @_;
if( !$self->has_relationship( $rel ) ) {
- $self->throw_exception("No such relationship '$rel'");
+ $self->throw_exception("No such relationship '$rel' on " . $self->source_name);
}
return $self->schema->source($self->relationship_info($rel)->{source});
}
=cut
sub handle {
- return new DBIx::Class::ResultSourceHandle({
+ return DBIx::Class::ResultSourceHandle->new({
schema => $_[0]->schema,
source_moniker => $_[0]->source_name
});
sub throw_exception {
my $self = shift;
+
if (defined $self->schema) {
$self->schema->throw_exception(@_);
- } else {
- croak(@_);
+ }
+ else {
+ DBIx::Class::Exception->throw(@_);
}
}
__PACKAGE__->column_info_from_storage(1);
Enables the on-demand automatic loading of the above column
-metadata from storage as neccesary. This is *deprecated*, and
+metadata from storage as necessary. This is *deprecated*, and
should not be used. It will be removed before 1.0.