X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=233597e45c0943b635a34155a17d193d565e2b10;hb=cdacba7e0c9b7bc947ae47238be4c6a25f9c7b13;hp=e03a16d2a489fbcaf51e1bc6a6ee12b1e2f30a97;hpb=ce65bba6aa64106758695dce4e1c0ccadad0d4c6;p=dbsrgits%2FDBIx-Class-Historic.git

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index e03a16d..233597e 100644
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -3,217 +3,381 @@ package DBIx::Class::ResultSet;
 use strict;
 use warnings;
 use overload
-        '0+'     => \&count,
-        'bool'   => sub { 1; },
+        '0+'     => "count",
+        'bool'   => "_bool",
         fallback => 1;
+use Carp::Clan qw/^DBIx::Class/;
 use Data::Page;
 use Storable;
-use Scalar::Util qw/weaken/;
-
+use DBIx::Class::ResultSetColumn;
+use DBIx::Class::ResultSourceHandle;
+use List::Util ();
+use Scalar::Util ();
 use base qw/DBIx::Class/;
-__PACKAGE__->load_components(qw/AccessorGroup/);
-__PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/);
+
+__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</search>
-or a C<has_many> 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<resultset> on a L<DBIx::Class::Schema> and passing in a
+L<Source|DBIx::Class::Manual::Glossary/Source> 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</search> on an existing
+ResultSet. The new one will contain all the conditions of the
+original, plus any new conditions added in the C<search> call.
+
+A ResultSet is also an iterator. L</next> is used to return all the
+L<DBIx::Class::Row>s the ResultSet represents.
+
+The query that the ResultSet represents is B<only> executed against
+the database when these methods are called:
+
+=over
+
+=item L</find>
+
+=item L</next>
+
+=item L</all>
+
+=item L</count>
+
+=item L</single>
+
+=item L</first>
+
+=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,
+    });
+  }
+
+=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</search>, L</count>, L</get_column>, L</all>, L</create>.
+
+=head1 OVERLOADING
+
+If a resultset is used in a numeric context it returns the L</count>.
+However, if it is used in a booleand context it is always true.  So if
+you want to check if a resultset has any results use C<if $rs != 0>.
+C<if $rs> will always be true.
 
 =head1 METHODS
 
 =head2 new
 
-=head3 Arguments: ($source, \%$attrs)
+=over 4
+
+=item Arguments: $source, \%$attrs
+
+=item Return Value: $rs
+
+=back
 
 The resultset constructor. Takes a source object (usually a
-L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see L</ATTRIBUTES>
-below).  Does not perform any queries -- these are executed as needed by the
-other methods.
+L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see
+L</ATTRIBUTES> below).  Does not perform any queries -- these are
+executed as needed by the other methods.
 
 Generally you won't need to construct a resultset manually.  You'll
 automatically get one from e.g. a L</search> called in scalar context:
 
   my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
 
+IMPORTANT: If called on an object, proxies to new_result instead so
+
+  my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
+
+will return a CD object, not a ResultSet.
+
 =cut
 
 sub new {
   my $class = shift;
   return $class->new_result(@_) if ref $class;
-  
-  my ($source, $attrs) = @_;
-  weaken $source;
-  $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
-  #use Data::Dumper; warn Dumper($attrs);
-  my $alias = ($attrs->{alias} ||= 'me');
-  
-  $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols};
-  delete $attrs->{as} if $attrs->{columns};
-  $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select};
-  $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ]
-    if $attrs->{columns};
-  $attrs->{as} ||= [ map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ];
-  if (my $include = delete $attrs->{include_columns}) {
-    push(@{$attrs->{select}}, @$include);
-    push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include);
-  }
-  #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
-
-  $attrs->{from} ||= [ { $alias => $source->from } ];
-  $attrs->{seen_join} ||= {};
-  my %seen;
-  if (my $join = delete $attrs->{join}) {
-    foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) {
-      if (ref $j eq 'HASH') {
-        $seen{$_} = 1 foreach keys %$j;
-      } else {
-        $seen{$j} = 1;
-      }
-    }
-    push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join}));
-  }
-  
-  $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
-  $attrs->{order_by} = [ $attrs->{order_by} ] if $attrs->{order_by} and !ref($attrs->{order_by});
-  $attrs->{order_by} ||= [];
 
-  my $collapse = $attrs->{collapse} || {};
-  if (my $prefetch = delete $attrs->{prefetch}) {
-    my @pre_order;
-    foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
-      if ( ref $p eq 'HASH' ) {
-        foreach my $key (keys %$p) {
-          push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
-            unless $seen{$key};
-        }
-      } else {
-        push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias}))
-            unless $seen{$p};
-      }
-      my @prefetch = $source->resolve_prefetch(
-           $p, $attrs->{alias}, {}, \@pre_order, $collapse);
-      push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
-      push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
-    }
-    push(@{$attrs->{order_by}}, @pre_order);
-  }
-  $attrs->{collapse} = $collapse;
-#  use Data::Dumper; warn Dumper($collapse) if keys %{$collapse};
+  my ($source, $attrs) = @_;
+  $source = $source->handle 
+    unless $source->isa('DBIx::Class::ResultSourceHandle');
+  $attrs = { %{$attrs||{}} };
 
   if ($attrs->{page}) {
     $attrs->{rows} ||= 10;
-    $attrs->{offset} ||= 0;
-    $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
   }
 
-  bless {
-    result_source => $source,
-    result_class => $attrs->{result_class} || $source->result_class,
+  $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,
     cond => $attrs->{where},
-    from => $attrs->{from},
-    collapse => $collapse,
     count => undef,
-    page => delete $attrs->{page},
     pager => undef,
     attrs => $attrs
-  }, $class;
+  };
+
+  bless $self, $class;
+
+  $self->result_class(
+    $attrs->{result_class} || $source->resolve->result_class
+  );
+
+  return $self;
 }
 
 =head2 search
 
-  my @cds    = $rs->search({ year => 2001 }); # "... WHERE year = 2001"
-  my $new_rs = $rs->search({ year => 2005 });
+=over 4
+
+=item Arguments: $cond, \%attrs?
+
+=item Return Value: $resultset (scalar context), @row_objs (list context)
+
+=back
+
+  my @cds    = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001"
+  my $new_rs = $cd_rs->search({ year => 2005 });
+
+  my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
+                 # year = 2005 OR year = 2004
 
 If you need to pass in additional attributes but no additional condition,
-call it as C<search(undef, \%attrs);>.
+call it as C<search(undef, \%attrs)>.
 
   # "SELECT name, artistid FROM $artist_table"
   my @all_artists = $schema->resultset('Artist')->search(undef, {
     columns => [qw/name artistid/],
   });
 
+For a list of attributes that can be passed to C<search>, see
+L</ATTRIBUTES>. For more examples of using this function, see
+L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
+documentation for the first argument, see L<SQL::Abstract>.
+
+For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
+
 =cut
 
 sub search {
   my $self = shift;
+  my $rs = $self->search_rs( @_ );
+  return (wantarray ? $rs->all : $rs);
+}
 
-  my $rs;
-  if( @_ ) {
-    
-    my $attrs = { %{$self->{attrs}} };
-    my $having = delete $attrs->{having};
-    $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH';
+=head2 search_rs
+
+=over 4
+
+=item Arguments: $cond, \%attrs?
+
+=item Return Value: $resultset
+
+=back
+
+This method does the same exact thing as search() except it will
+always return a resultset, even in list context.
+
+=cut
+
+sub search_rs {
+  my $self = shift;
+
+  my $attrs = {};
+  $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
+  my $our_attrs = { %{$self->{attrs}} };
+  my $having = delete $our_attrs->{having};
+  my $where = delete $our_attrs->{where};
+
+  my $rows;
+
+  my %safe = (alias => 1, cache => 1);
 
-    my $where = (@_
-                  ? ((@_ == 1 || ref $_[0] eq "HASH")
+  unless (
+    (@_ && defined($_[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 +select +as/) {
+    next unless exists $attrs->{$key};
+    $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
+  }
+
+  my $cond = (@_
+    ? (
+        (@_ == 1 || ref $_[0] eq "HASH")
+          ? (
+              (ref $_[0] eq 'HASH')
+                ? (
+                    (keys %{ $_[0] }  > 0)
                       ? shift
-                      : ((@_ % 2)
-                          ? $self->throw_exception(
-                              "Odd number of arguments to search")
-                          : {@_}))
-                  : undef());
-    if (defined $where) {
-      $attrs->{where} = (defined $attrs->{where}
-                ? { '-and' =>
-                    [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
-                        $where, $attrs->{where} ] }
-                : $where);
-    }
+                      : undef
+                   )
+                :  shift
+             )
+          : (
+              (@_ % 2)
+                ? $self->throw_exception("Odd number of arguments to search")
+                : {@_}
+             )
+      )
+    : undef
+  );
 
-    if (defined $having) {
-      $attrs->{having} = (defined $attrs->{having}
-                ? { '-and' =>
-                    [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
-                        $having, $attrs->{having} ] }
-                : $having);
-    }
+  if (defined $where) {
+    $new_attrs->{where} = (
+      defined $new_attrs->{where}
+        ? { '-and' => [
+              map {
+                ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
+              } $where, $new_attrs->{where}
+            ]
+          }
+        : $where);
+  }
 
-    $rs = (ref $self)->new($self->result_source, $attrs);
+  if (defined $cond) {
+    $new_attrs->{where} = (
+      defined $new_attrs->{where}
+        ? { '-and' => [
+              map {
+                ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
+              } $cond, $new_attrs->{where}
+            ]
+          }
+        : $cond);
   }
-  else {
-    $rs = $self;
-    $rs->reset;
+
+  if (defined $having) {
+    $new_attrs->{having} = (
+      defined $new_attrs->{having}
+        ? { '-and' => [
+              map {
+                ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
+              } $having, $new_attrs->{having}
+            ]
+          }
+        : $having);
   }
-  return (wantarray ? $rs->all : $rs);
+
+  my $rs = (ref $self)->new($self->result_source, $new_attrs);
+  if ($rows) {
+    $rs->set_cache($rows);
+  }
+  return $rs;
 }
 
 =head2 search_literal
 
-  my @obj    = $rs->search_literal($literal_where_cond, @bind);
-  my $new_rs = $rs->search_literal($literal_where_cond, @bind);
+=over 4
+
+=item Arguments: $sql_fragment, @bind_values
+
+=item Return Value: $resultset (scalar context), @row_objs (list context)
+
+=back
+
+  my @cds   = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/);
+  my $newrs = $artist_rs->search_literal('name = ?', 'Metallica');
 
 Pass a literal chunk of SQL to be added to the conditional part of the
-resultset.
+resultset query.
+
+CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
+only be used in that context. There are known problems using C<search_literal>
+in chained queries; it can result in bind values in the wrong order.  See
+L<DBIx::Class::Manual::Cookbook/Searching> and
+L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
+require C<search_literal>.
 
 =cut
 
@@ -226,70 +390,224 @@ sub search_literal {
 
 =head2 find
 
-=head3 Arguments: (@colvalues) | (\%cols, \%attrs?)
+=over 4
+
+=item Arguments: @values | \%cols, \%attrs?
+
+=item Return Value: $row_object | undef
 
-Finds a row based on its primary key or unique constraint. For example:
+=back
+
+Finds a row based on its primary key or unique constraint. For example, to find
+a row by its primary key:
 
   my $cd = $schema->resultset('CD')->find(5);
 
-Also takes an optional C<key> attribute, to search by a specific key or unique
-constraint. For example:
+You can also find a row by a specific unique constraint using the C<key>
+attribute. For example:
+
+  my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
+    key => 'cd_artist_title'
+  });
+
+Additionally, you can specify the columns explicitly by name:
 
   my $cd = $schema->resultset('CD')->find(
     {
       artist => 'Massive Attack',
       title  => 'Mezzanine',
     },
-    { key => 'artist_title' }
+    { key => 'cd_artist_title' }
   );
 
-See also L</find_or_create> and L</update_or_create>.
+If the C<key> is specified as C<primary>, it searches only on the primary key.
+
+If no C<key> is specified, it searches on all unique constraints defined on the
+source for which column data is provided, including the primary key.
+
+If your table does not have a primary key, you B<must> provide a value for the
+C<key> attribute matching one of the unique constraints on the source.
+
+In addition to C<key>, L</find> recognizes and applies standard
+L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
+
+Note: If your query does not return only one row, a warning is generated:
+
+  Query returned more than one row
+
+See also L</find_or_create> and L</update_or_create>. For information on how to
+declare unique constraints, see
+L<DBIx::Class::ResultSource/add_unique_constraint>.
 
 =cut
 
 sub find {
-  my ($self, @vals) = @_;
-  my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
+  my $self = shift;
+  my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
 
-  my @cols = $self->result_source->primary_columns;
-  if (exists $attrs->{key}) {
-    my %uniq = $self->result_source->unique_constraints;
-    $self->throw_exception( "Unknown key $attrs->{key} on '" . $self->result_source->name . "'" )
-      unless exists $uniq{$attrs->{key}};
-    @cols = @{ $uniq{$attrs->{key}} };
+  # Default to the primary key, but allow a specific key
+  my @cols = exists $attrs->{key}
+    ? $self->result_source->unique_constraint_columns($attrs->{key})
+    : $self->result_source->primary_columns;
+  $self->throw_exception(
+    "Can't find unless a primary key is defined or unique constraint is specified"
+  ) unless @cols;
+
+  # Parse out a hashref from input
+  my $input_query;
+  if (ref $_[0] eq 'HASH') {
+    $input_query = { %{$_[0]} };
   }
-  #use Data::Dumper; warn Dumper($attrs, @vals, @cols);
-  $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" )
-    unless @cols;
+  elsif (@_ == @cols) {
+    $input_query = {};
+    @{$input_query}{@cols} = @_;
+  }
+  else {
+    # Compatibility: Allow e.g. find(id => $value)
+    carp "Find by key => value deprecated; please use a hashref instead";
+    $input_query = {@_};
+  }
+
+  my (%related, $info);
+
+  KEY: foreach my $key (keys %$input_query) {
+    if (ref($input_query->{$key})
+        && ($info = $self->result_source->relationship_info($key))) {
+      my $val = delete $input_query->{$key};
+      next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
+      my $rel_q = $self->result_source->resolve_condition(
+                    $info->{cond}, $val, $key
+                  );
+      die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
+      @related{keys %$rel_q} = values %$rel_q;
+    }
+  }
+  if (my @keys = keys %related) {
+    @{$input_query}{@keys} = 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;
-  if (ref $vals[0] eq 'HASH') {
-    $query = { %{$vals[0]} };
-  } elsif (@cols == @vals) {
-    $query = {};
-    @{$query}{@cols} = @vals;
-  } else {
-    $query = {@vals};
+  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);
   }
-  foreach my $key (grep { ! m/\./ } keys %$query) {
-    $query->{"$self->{attrs}{alias}.$key"} = delete $query->{$key};
+  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, $alias);
   }
-  #warn Dumper($query);
-  
+
+  # Run the query
   if (keys %$attrs) {
-      my $rs = $self->search($query,$attrs);
-      return keys %{$rs->{collapse}} ? $rs->next : $rs->single;
-  } else {
-      return keys %{$self->{collapse}} ? $self->search($query)->next : $self->single($query);
+    my $rs = $self->search($query, $attrs);
+    if (keys %{$rs->_resolved_attrs->{collapse}}) {
+      my $row = $rs->next;
+      carp "Query returned more than one row" if $rs->next;
+      return $row;
+    }
+    else {
+      return $rs->single;
+    }
+  }
+  else {
+    if (keys %{$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);
+    }
+  }
+}
+
+# _add_alias
+#
+# Add the specified alias to the specified query hash. A copy is made so the
+# original query is not modified.
+
+sub _add_alias {
+  my ($self, $query, $alias) = @_;
+
+  my %aliased = %$query;
+  foreach my $col (grep { ! m/\./ } keys %aliased) {
+    $aliased{"$alias.$col"} = delete $aliased{$col};
+  }
+
+  return \%aliased;
+}
+
+# _unique_queries
+#
+# Build a list of queries which satisfy unique constraints.
+
+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;
+  foreach my $name (@constraint_names) {
+    my @unique_cols = $self->result_source->unique_constraint_columns($name);
+    my $unique_query = $self->_build_unique_query($query, \@unique_cols);
+
+    my $num_cols = scalar @unique_cols;
+    my $num_query = scalar keys %$unique_query;
+
+    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, $unique_query;
+    }
   }
+
+  return @unique_queries;
+}
+
+# _build_unique_query
+#
+# Constrain the specified query hash based on the specified column names.
+
+sub _build_unique_query {
+  my ($self, $query, $unique_cols) = @_;
+
+  return {
+    map  { $_ => $query->{$_} }
+    grep { exists $query->{$_} }
+      @$unique_cols
+  };
 }
 
 =head2 search_related
 
-  $rs->search_related('relname', $cond?, $attrs?);
+=over 4
+
+=item Arguments: $rel, $cond, \%attrs?
+
+=item Return Value: $new_resultset
+
+=back
 
-Search the specified relationship. Optionally specify a condition for matching
-records.
+  $new_rs = $cd_rs->search_related('artist', {
+    name => 'Emo-R-Us',
+  });
+
+Searches the specified relationship, optionally specifying a condition and
+attributes for matching records. See L</ATTRIBUTES> for more information.
 
 =cut
 
@@ -297,33 +615,91 @@ 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
 
-Returns a storage-driven cursor to the given resultset.
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $cursor
+
+=back
+
+Returns a storage-driven cursor to the given resultset. See
+L<DBIx::Class::Cursor> for more information.
 
 =cut
 
 sub cursor {
   my ($self) = @_;
-  my $attrs = { %{$self->{attrs}} };
+
+  my $attrs = { %{$self->_resolved_attrs} };
   return $self->{cursor}
-    ||= $self->result_source->storage->select($self->{from}, $attrs->{select},
+    ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
           $attrs->{where},$attrs);
 }
 
 =head2 single
 
-Inflates the first result without creating a cursor
+=over 4
+
+=item Arguments: $cond?
+
+=item Return Value: $row_object?
+
+=back
+
+  my $cd = $schema->resultset('CD')->single({ year => 2001 });
+
+Inflates the first result without creating a cursor if the resultset has
+any records in it; if not returns nothing. Used by L</find> as a lean version of
+L</search>.
+
+While this method can take an optional search condition (just like L</search>)
+being a fast-code-path it does not recognize search attributes. If you need to
+add extra joins or similar, call L</search> and then chain-call L</single> on the
+L<DBIx::Class::ResultSet> returned.
+
+=over
+
+=item B<Note>
+
+As of 0.08100, this method enforces the assumption that the preceeding
+query returns only one row. If more than one row is returned, you will receive
+a warning:
+
+  Query returned more than one row
+
+In this case, you should be using L</first> or L</find> instead, or if you really
+know what you are doing, use the L</rows> attribute to explicitly limit the size 
+of the resultset.
+
+=back
 
 =cut
 
 sub single {
   my ($self, $where) = @_;
-  my $attrs = { %{$self->{attrs}} };
+  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}) {
       $attrs->{where} = {
-        '-and' => 
+        '-and' =>
             [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
                $where, delete $attrs->{where} ]
       };
@@ -331,153 +707,344 @@ sub single {
       $attrs->{where} = $where;
     }
   }
+
+#  XXX: Disabled since it doesn't infer uniqueness in all cases
+#  unless ($self->_is_unique_query($attrs->{where})) {
+#    carp "Query not guaranteed to return a single row"
+#      . "; please declare your unique constraints or use search instead";
+#  }
+
   my @data = $self->result_source->storage->select_single(
-          $self->{from}, $attrs->{select},
-          $attrs->{where},$attrs);
-  return (@data ? $self->_construct_object(@data) : ());
+    $attrs->{from}, $attrs->{select},
+    $attrs->{where}, $attrs
+  );
+
+  return (@data ? ($self->_construct_object(@data))[0] : undef);
 }
 
+# _is_unique_query
+#
+# Try to determine if the specified query is guaranteed to be unique, based on
+# the declared unique constraints.
 
-=head2 search_like
+sub _is_unique_query {
+  my ($self, $query) = @_;
 
-Perform a search, but use C<LIKE> instead of equality as the condition. Note
-that this is simply a convenience method; you most likely want to use
-L</search> with specific operators.
+  my $collapsed = $self->_collapse_query($query);
+  my $alias = $self->{attrs}{alias};
 
-For more information, see L<DBIx::Class::Manual::Cookbook>.
+  foreach my $name ($self->result_source->unique_constraint_names) {
+    my @unique_cols = map {
+      "$alias.$_"
+    } $self->result_source->unique_constraint_columns($name);
 
-=cut
+    # Count the values for each unique column
+    my %seen = map { $_ => 0 } @unique_cols;
 
-sub search_like {
-  my $class = shift;
-  my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
-  my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
-  $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
-  return $class->search($query, { %$attrs });
+    foreach my $key (keys %$collapsed) {
+      my $aliased = $key =~ /\./ ? $key : "$alias.$key";
+      next unless exists $seen{$aliased};  # Additional constraints are okay
+      $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
+    }
+
+    # If we get 0 or more than 1 value for a column, it's not necessarily unique
+    return 1 unless grep { $_ != 1 } values %seen;
+  }
+
+  return 0;
 }
 
-=head2 slice
+# _collapse_query
+#
+# Recursively collapse the query, accumulating values for each column.
 
-=head3 Arguments: ($first, $last)
+sub _collapse_query {
+  my ($self, $query, $collapsed) = @_;
 
-Returns a subset of elements from the resultset.
+  $collapsed ||= {};
 
-=cut
+  if (ref $query eq 'ARRAY') {
+    foreach my $subquery (@$query) {
+      next unless ref $subquery;  # -or
+#      warn "ARRAY: " . Dumper $subquery;
+      $collapsed = $self->_collapse_query($subquery, $collapsed);
+    }
+  }
+  elsif (ref $query eq 'HASH') {
+    if (keys %$query and (keys %$query)[0] eq '-and') {
+      foreach my $subquery (@{$query->{-and}}) {
+#        warn "HASH: " . Dumper $subquery;
+        $collapsed = $self->_collapse_query($subquery, $collapsed);
+      }
+    }
+    else {
+#      warn "LEAF: " . Dumper $query;
+      foreach my $col (keys %$query) {
+        my $value = $query->{$col};
+        $collapsed->{$col}{$value}++;
+      }
+    }
+  }
 
-sub slice {
-  my ($self, $min, $max) = @_;
-  my $attrs = { %{ $self->{attrs} || {} } };
-  $attrs->{offset} ||= 0;
-  $attrs->{offset} += $min;
-  $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
-  my $slice = (ref $self)->new($self->result_source, $attrs);
-  return (wantarray ? $slice->all : $slice);
+  return $collapsed;
 }
 
-=head2 next
+=head2 get_column
 
-Returns the next element in the resultset (C<undef> is there is none).
+=over 4
 
-Can be used to efficiently iterate over records in the resultset:
+=item Arguments: $cond?
 
-  my $rs = $schema->resultset('CD')->search;
-  while (my $cd = $rs->next) {
-    print $cd->title;
-  }
+=item Return Value: $resultsetcolumn
+
+=back
+
+  my $max_length = $rs->get_column('length')->max;
+
+Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
 
 =cut
 
-sub next {
-  my ($self) = @_;
-  if (@{$self->{all_cache} || []}) {
-    $self->{all_cache_position} ||= 0;
-    return $self->{all_cache}->[$self->{all_cache_position}++];
+sub get_column {
+  my ($self, $column) = @_;
+  my $new = DBIx::Class::ResultSetColumn->new($self, $column);
+  return $new;
+}
+
+=head2 search_like
+
+=over 4
+
+=item Arguments: $cond, \%attrs?
+
+=item Return Value: $resultset (scalar context), @row_objs (list context)
+
+=back
+
+  # WHERE title LIKE '%blue%'
+  $cd_rs = $rs->search_like({ title => '%blue%'});
+
+Performs a search, but uses C<LIKE> instead of C<=> as the condition. Note
+that this is simply a convenience method retained for ex Class::DBI users.
+You most likely want to use L</search> with specific operators.
+
+For more information, see L<DBIx::Class::Manual::Cookbook>.
+
+=cut
+
+sub search_like {
+  my $class = shift;
+  my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+  my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_};
+  $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
+  return $class->search($query, { %$attrs });
+}
+
+=head2 slice
+
+=over 4
+
+=item Arguments: $first, $last
+
+=item Return Value: $resultset (scalar context), @row_objs (list context)
+
+=back
+
+Returns a resultset or object list representing a subset of elements from the
+resultset slice is called on. Indexes are from 0, i.e., to get the first
+three records, call:
+
+  my ($one, $two, $three) = $rs->slice(0, 2);
+
+=cut
+
+sub slice {
+  my ($self, $min, $max) = @_;
+  my $attrs = {}; # = { %{ $self->{attrs} || {} } };
+  $attrs->{offset} = $self->{attrs}{offset} || 0;
+  $attrs->{offset} += $min;
+  $attrs->{rows} = ($max ? ($max - $min + 1) : 1);
+  return $self->search(undef(), $attrs);
+  #my $slice = (ref $self)->new($self->result_source, $attrs);
+  #return (wantarray ? $slice->all : $slice);
+}
+
+=head2 next
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $result?
+
+=back
+
+Returns the next element in the resultset (C<undef> is there is none).
+
+Can be used to efficiently iterate over records in the resultset:
+
+  my $rs = $schema->resultset('CD')->search;
+  while (my $cd = $rs->next) {
+    print $cd->title;
+  }
+
+Note that you need to store the resultset object, and call C<next> on it.
+Calling C<< resultset('Table')->next >> repeatedly will always return the
+first record from the resultset.
+
+=cut
+
+sub next {
+  my ($self) = @_;
+  if (my $cache = $self->get_cache) {
+    $self->{all_cache_position} ||= 0;
+    return $cache->[$self->{all_cache_position}++];
   }
   if ($self->{attrs}{cache}) {
     $self->{all_cache_position} = 1;
     return ($self->all)[0];
   }
-  my @row = (exists $self->{stashed_row}
-               ? @{delete $self->{stashed_row}}
-               : $self->cursor->next);
-#  warn Dumper(\@row); use Data::Dumper;
-  return unless (@row);
-  return $self->_construct_object(@row);
+  if ($self->{stashed_objects}) {
+    my $obj = shift(@{$self->{stashed_objects}});
+    delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
+    return $obj;
+  }
+  my @row = (
+    exists $self->{stashed_row}
+      ? @{delete $self->{stashed_row}}
+      : $self->cursor->next
+  );
+  return undef unless (@row);
+  my ($row, @more) = $self->_construct_object(@row);
+  $self->{stashed_objects} = \@more if @more;
+  return $row;
 }
 
 sub _construct_object {
   my ($self, @row) = @_;
-  my @as = @{ $self->{attrs}{as} };
-  
-  my $info = $self->_collapse_result(\@as, \@row);
-  
-  my $new = $self->result_class->inflate_result($self->result_source, @$info);
-  
-  $new = $self->{attrs}{record_filter}->($new)
-    if exists $self->{attrs}{record_filter};
-  return $new;
+  my $info = $self->_collapse_result($self->{_attrs}{as}, \@row);
+  my @new = $self->result_class->inflate_result($self->result_source, @$info);
+  @new = $self->{_attrs}{record_filter}->(@new)
+    if exists $self->{_attrs}{record_filter};
+  return @new;
 }
 
 sub _collapse_result {
-  my ($self, $as, $row, $prefix) = @_;
-
-  my %const;
+  my ($self, $as_proto, $row) = @_;
 
   my @copy = @$row;
-  foreach my $this_as (@$as) {
-    my $val = shift @copy;
-    if (defined $prefix) {
-      if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) {
-        my $remain = $1;
-        $remain =~ /^(?:(.*)\.)?([^.]+)$/;
-        $const{$1||''}{$2} = $val;
-      }
-    } else {
-      $this_as =~ /^(?:(.*)\.)?([^.]+)$/;
-      $const{$1||''}{$2} = $val;
-    }
-  }
 
-  my $info = [ {}, {} ];
-  foreach my $key (keys %const) {
-    if (length $key) {
-      my $target = $info;
-      my @parts = split(/\./, $key);
-      foreach my $p (@parts) {
-        $target = $target->[1]->{$p} ||= [];
+  # 'foo'         => [ undef, 'foo' ]
+  # 'foo.bar'     => [ 'foo', 'bar' ]
+  # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
+
+  my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
+
+  my %collapse = %{$self->{_attrs}{collapse}||{}};
+
+  my @pri_index;
+
+  # if we're doing collapsing (has_many prefetch) we need to grab records
+  # until the PK changes, so fill @pri_index. if not, we leave it empty so
+  # we know we don't have to bother.
+
+  # the reason for not using the collapse stuff directly is because if you
+  # had for e.g. two artists in a row with no cds, the collapse info for
+  # both would be NULL (undef) so you'd lose the second artist
+
+  # store just the index so we can check the array positions from the row
+  # without having to contruct the full hash
+
+  if (keys %collapse) {
+    my %pri = map { ($_ => 1) } $self->result_source->primary_columns;
+    foreach my $i (0 .. $#construct_as) {
+      next if defined($construct_as[$i][0]); # only self table
+      if (delete $pri{$construct_as[$i][1]}) {
+        push(@pri_index, $i);
       }
-      $target->[0] = $const{$key};
-    } else {
-      $info->[0] = $const{$key};
+      last unless keys %pri; # short circuit (Johnny Five Is Alive!)
     }
   }
 
-  my @collapse = (defined($prefix)
-                   ? (map { (m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()); }
-                       keys %{$self->{collapse}})
-                   : keys %{$self->{collapse}});
-  if (@collapse) {
-    my ($c) = sort { length $a <=> length $b } @collapse;
-    my $target = $info;
-    foreach my $p (split(/\./, $c)) {
-      $target = $target->[1]->{$p} ||= [];
+  # no need to do an if, it'll be empty if @pri_index is empty anyway
+
+  my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
+
+  my @const_rows;
+
+  do { # no need to check anything at the front, we always want the first row
+
+    my %const;
+  
+    foreach my $this_as (@construct_as) {
+      $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
     }
-    my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c);
-    my @co_key = @{$self->{collapse}{$c_prefix}};
-    my %co_check = map { ($_, $target->[0]->{$_}); } @co_key;
-    my $tree = $self->_collapse_result($as, $row, $c_prefix);
-    my (@final, @raw);
-    while ( !(grep {
-                !defined($tree->[0]->{$_})
-                || $co_check{$_} ne $tree->[0]->{$_}
-              } @co_key) ) {
-      push(@final, $tree);
-      last unless (@raw = $self->cursor->next);
-      $row = $self->{stashed_row} = \@raw;
-      $tree = $self->_collapse_result($as, $row, $c_prefix);
-      #warn Data::Dumper::Dumper($tree, $row);
+
+    push(@const_rows, \%const);
+
+  } until ( # no pri_index => no collapse => drop straight out
+      !@pri_index
+    or
+      do { # get another row, stash it, drop out if different PK
+
+        @copy = $self->cursor->next;
+        $self->{stashed_row} = \@copy;
+
+        # last thing in do block, counts as true if anything doesn't match
+
+        # check xor defined first for NULL vs. NOT NULL then if one is
+        # defined the other must be so check string equality
+
+        grep {
+          (defined $pri_vals{$_} ^ defined $copy[$_])
+          || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
+        } @pri_index;
+      }
+  );
+
+  my $alias = $self->{attrs}{alias};
+  my $info = [];
+
+  my %collapse_pos;
+
+  my @const_keys;
+
+  foreach my $const (@const_rows) {
+    scalar @const_keys or do {
+      @const_keys = sort { length($a) <=> length($b) } keys %$const;
+    };
+    foreach my $key (@const_keys) {
+      if (length $key) {
+        my $target = $info;
+        my @parts = split(/\./, $key);
+        my $cur = '';
+        my $data = $const->{$key};
+        foreach my $p (@parts) {
+          $target = $target->[1]->{$p} ||= [];
+          $cur .= ".${p}";
+          if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) { 
+            # collapsing at this point and on final part
+            my $pos = $collapse_pos{$cur};
+            CK: foreach my $ck (@ckey) {
+              if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
+                $collapse_pos{$cur} = $data;
+                delete @collapse_pos{ # clear all positioning for sub-entries
+                  grep { m/^\Q${cur}.\E/ } keys %collapse_pos
+                };
+                push(@$target, []);
+                last CK;
+              }
+            }
+          }
+          if (exists $collapse{$cur}) {
+            $target = $target->[-1];
+          }
+        }
+        $target->[0] = $data;
+      } else {
+        $info->[0] = $const->{$key};
+      }
     }
-    @$target = @final;
   }
 
   return $info;
@@ -485,18 +1052,57 @@ sub _collapse_result {
 
 =head2 result_source
 
-Returns a reference to the result source for this recordset.
+=over 4
+
+=item Arguments: $result_source?
+
+=item Return Value: $result_source
+
+=back
+
+An accessor for the primary ResultSource object from which this ResultSet
+is derived.
+
+=head2 result_class
+
+=over 4
+
+=item Arguments: $result_class?
+
+=item Return Value: $result_class
+
+=back
+
+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.
 
 =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
 
+=over 4
+
+=item Arguments: $cond, \%attrs??
+
+=item Return Value: $count
+
+=back
+
 Performs an SQL C<COUNT> 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<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY>
+Note: When using C<count> with C<group_by>, L<DBIx::Class> emulates C<GROUP BY>
 using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do
 not support C<DISTINCT> with multiple columns. If you are using such a
 database, you should only use columns from the main table in your C<group_by>
@@ -507,37 +1113,40 @@ clause.
 sub count {
   my $self = shift;
   return $self->search(@_)->count if @_ and defined $_[0];
-  return scalar @{ $self->get_cache } if @{ $self->get_cache };
-
+  return scalar @{ $self->get_cache } if $self->get_cache;
   my $count = $self->_count;
   return 0 unless $count;
 
-  $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
+  # need to take offset from resolved attrs
+
+  $count -= $self->{_attrs}{offset} if $self->{_attrs}{offset};
   $count = $self->{attrs}{rows} if
     $self->{attrs}{rows} and $self->{attrs}{rows} < $count;
+  $count = 0 if ($count < 0);
   return $count;
 }
 
 sub _count { # Separated out so pager can get the full count
   my $self = shift;
   my $select = { count => '*' };
-  my $attrs = { %{ $self->{attrs} } };
+
+  my $attrs = { %{$self->_resolved_attrs} };
   if (my $group_by = delete $attrs->{group_by}) {
     delete $attrs->{having};
     my @distinct = (ref $group_by ?  @$group_by : ($group_by));
     # todo: try CONCAT for multi-column pk
     my @pk = $self->result_source->primary_columns;
     if (@pk == 1) {
+      my $alias = $attrs->{alias};
       foreach my $column (@distinct) {
-        if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) {
+        if ($column =~ qr/^(?:\Q${alias}.\E)?$pk[0]$/) {
           @distinct = ($column);
           last;
         }
-      } 
+      }
     }
 
     $select = { count => { distinct => \@distinct } };
-    #use Data::Dumper; die Dumper $select;
   }
 
   $attrs->{select} = $select;
@@ -545,14 +1154,28 @@ 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 ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next;
+
+  my $tmp_rs = (ref $self)->new($self->result_source, $attrs);
+  my ($count) = $tmp_rs->cursor->next;
   return $count;
 }
 
+sub _bool {
+  return 1;
+}
+
 =head2 count_literal
 
-Calls L</search_literal> with the passed arguments, then L</count>.
+=over 4
+
+=item Arguments: $sql_fragment, @bind_values
+
+=item Return Value: $count
+
+=back
+
+Counts the results in a literal query. Equivalent to calling L</search_literal>
+with the passed arguments, then L</count>.
 
 =cut
 
@@ -560,23 +1183,36 @@ sub count_literal { shift->search_literal(@_)->count; }
 
 =head2 all
 
-Returns all elements in the resultset. Called implictly if the resultset
+=over 4
+
+=item Arguments: none
+
+=item Return Value: @objects
+
+=back
+
+Returns all elements in the resultset. Called implicitly if the resultset
 is returned in list context.
 
 =cut
 
 sub all {
-  my ($self) = @_;
-  return @{ $self->get_cache } if @{ $self->get_cache };
+  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;
 
-  if (keys %{$self->{collapse}}) {
+  # TODO: don't call resolve here
+  if (keys %{$self->_resolved_attrs->{collapse}}) {
+#  if ($self->{attrs}{prefetch}) {
       # Using $self->cursor->all is really just an optimisation.
       # If we're collapsing has_many prefetches it probably makes
       # very little difference, and this is cleaner than hacking
       # _construct_object to survive the approach
-    $self->cursor->reset;
     my @row = $self->cursor->next;
     while (@row) {
       push(@obj, $self->_construct_object(@row));
@@ -594,12 +1230,21 @@ sub all {
 
 =head2 reset
 
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $self
+
+=back
+
 Resets the resultset's cursor, so you can iterate through the elements again.
 
 =cut
 
 sub reset {
   my ($self) = @_;
+  delete $self->{_attrs} if exists $self->{_attrs};
   $self->{all_cache_position} = 0;
   $self->cursor->reset;
   return $self;
@@ -607,7 +1252,16 @@ sub reset {
 
 =head2 first
 
-Resets the resultset and returns the first element.
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $object?
+
+=back
+
+Resets the resultset and returns an object for the first result (if the
+resultset returns anything).
 
 =cut
 
@@ -615,33 +1269,121 @@ sub first {
   return $_[0]->reset->next;
 }
 
+# _cond_for_update_delete
+#
+# update/delete require the condition to be modified to handle
+# the differing SQL syntax available.  This transforms the $self->{cond}
+# appropriately, returning the new condition.
+
+sub _cond_for_update_delete {
+  my ($self, $full_cond) = @_;
+  my $cond = {};
+
+  $full_cond ||= $self->{cond};
+  # No-op. No condition, we're updating/deleting everything
+  return $cond unless ref $full_cond;
+
+  if (ref $full_cond eq 'ARRAY') {
+    $cond = [
+      map {
+        my %hash;
+        foreach my $key (keys %{$_}) {
+          $key =~ /([^.]+)$/;
+          $hash{$1} = $_->{$key};
+        }
+        \%hash;
+      } @{$full_cond}
+    ];
+  }
+  elsif (ref $full_cond eq 'HASH') {
+    if ((keys %{$full_cond})[0] eq '-and') {
+      $cond->{-and} = [];
+
+      my @cond = @{$full_cond->{-and}};
+      for (my $i = 0; $i < @cond; $i++) {
+        my $entry = $cond[$i];
+
+        my $hash;
+        if (ref $entry eq 'HASH') {
+          $hash = $self->_cond_for_update_delete($entry);
+        }
+        else {
+          $entry =~ /([^.]+)$/;
+          $hash->{$1} = $cond[++$i];
+        }
+
+        push @{$cond->{-and}}, $hash;
+      }
+    }
+    else {
+      foreach my $key (keys %{$full_cond}) {
+        $key =~ /([^.]+)$/;
+        $cond->{$1} = $full_cond->{$key};
+      }
+    }
+  }
+  else {
+    $self->throw_exception(
+      "Can't update/delete on resultset with condition unless hash or array"
+    );
+  }
+
+  return $cond;
+}
+
+
 =head2 update
 
-=head3 Arguments: (\%values)
+=over 4
 
-Sets the specified columns in the resultset to the supplied values.
+=item Arguments: \%values
+
+=item Return Value: $storage_rv
+
+=back
+
+Sets the specified columns in the resultset to the supplied values in a
+single query. Return value will be true if the update succeeded or false
+if no records were updated; exact type of success value is storage-dependent.
 
 =cut
 
 sub update {
   my ($self, $values) = @_;
-  $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH';
+  $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(
-           $self->result_source->from, $values, $self->{cond});
+    $self->result_source, $values, $cond
+  );
 }
 
 =head2 update_all
 
-=head3 Arguments: (\%values)
+=over 4
+
+=item Arguments: \%values
+
+=item Return Value: 1
 
-Fetches all objects and updates them one at a time.  Note that C<update_all>
-will run cascade triggers while L</update> will not.
+=back
+
+Fetches all objects and updates them one at a time. Note that C<update_all>
+will run DBIC cascade triggers, while L</update> will not.
 
 =cut
 
 sub update_all {
   my ($self, $values) = @_;
-  $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH';
+  $self->throw_exception("Values for update must be a hash")
+    unless ref $values eq 'HASH';
   foreach my $obj ($self->all) {
     $obj->set_columns($values)->update;
   }
@@ -650,68 +1392,248 @@ sub update_all {
 
 =head2 delete
 
-Deletes the contents of the resultset from its result source.
+=over 4
+
+=item Arguments: none
+
+=item Return Value: 1
+
+=back
+
+Deletes the contents of the resultset from its result source. Note that this
+will not run DBIC cascade triggers. See L</delete_all> if you need triggers
+to run. See also L<DBIx::Class::Row/delete>.
+
+delete may not generate correct SQL for a query with joins or a resultset
+chained from a related resultset.  In this case it will generate a warning:-
+
+  WARNING! Currently $rs->delete() does not generate proper SQL on
+  joined resultsets, and may delete rows well outside of the contents
+  of $rs. Use at your own risk
+
+In these cases you may find that delete_all is more appropriate, or you
+need to respecify your query in a way that can be expressed without a join.
 
 =cut
 
 sub delete {
   my ($self) = @_;
-  my $del = {};
+  $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, $cond);
+  return 1;
+}
+
+=head2 delete_all
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: 1
+
+=back
+
+Fetches all objects and deletes them one at a time. Note that C<delete_all>
+will run DBIC cascade triggers, while L</delete> will not.
+
+=cut
+
+sub delete_all {
+  my ($self) = @_;
+  $_->delete for $self->all;
+  return 1;
+}
 
-  if (!ref($self->{cond})) {
+=head2 populate
 
-    # No-op. No condition, we're deleting everything
+=over 4
 
-  } elsif (ref $self->{cond} eq 'ARRAY') {
+=item Arguments: \@data;
 
-    $del = [ map { my %hash;
-      foreach my $key (keys %{$_}) {
-        $key =~ /([^.]+)$/;
-        $hash{$1} = $_->{$key};
-      }; \%hash; } @{$self->{cond}} ];
+=back
 
-  } elsif (ref $self->{cond} eq 'HASH') {
+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.
 
-    if ((keys %{$self->{cond}})[0] eq '-and') {
+In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
+to insert the data, as this is a faster method.  
 
-      $del->{-and} = [ map { my %hash;
-        foreach my $key (keys %{$_}) {
-          $key =~ /([^.]+)$/;
-          $hash{$1} = $_->{$key};
-        }; \%hash; } @{$self->{cond}{-and}} ];
+Otherwise, each set of data is inserted into the database using
+L<DBIx::Class::ResultSet/create>, and a arrayref of the resulting row
+objects is returned.
 
-    } else {
+Example:  Assuming an Artist Class that has many CDs Classes relating:
 
-      foreach my $key (keys %{$self->{cond}}) {
-        $key =~ /([^.]+)$/;
-        $del->{$1} = $self->{cond}{$key};
-      }
+  my $Artist_rs = $schema->resultset("Artist");
+  
+  ## Void Context Example 
+  $Artist_rs->populate([
+     { artistid => 4, name => 'Manufactured Crap', cds => [ 
+        { title => 'My First CD', year => 2006 },
+        { title => 'Yet More Tweeny-Pop crap', year => 2007 },
+      ],
+     },
+     { artistid => 5, name => 'Angsty-Whiny Girl', cds => [
+        { title => 'My parents sold me to a record company' ,year => 2005 },
+        { title => 'Why Am I So Ugly?', year => 2006 },
+        { title => 'I Got Surgery and am now Popular', year => 2007 }
+      ],
+     },
+  ]);
+  
+  ## Array Context Example
+  my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
+    { name => "Artist One"},
+    { name => "Artist Two"},
+    { name => "Artist Three", cds=> [
+    { title => "First CD", year => 2007},
+    { title => "Second CD", year => 2008},
+  ]}
+  ]);
+  
+  print $ArtistOne->name; ## response is 'Artist One'
+  print $ArtistThree->cds->count ## reponse is '2'
+
+For the arrayref of arrayrefs style,  the first element should be a list of the
+fieldsnames to which the remaining elements are rows being inserted.  For
+example:
+
+  $Arstist_rs->populate([
+    [qw/artistid name/],
+    [100, 'A Formally Unknown Singer'],
+    [101, 'A singer that jumped the shark two albums ago'],
+    [102, 'An actually cool singer.'],
+  ]);
+
+Please note an important effect on your data when choosing between void and
+wantarray context. Since void context goes straight to C<insert_bulk> in 
+L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
+c<insert>.  So if you are using something like L<DBIx-Class-UUIDColumns> to 
+create primary keys for you, you will find that your PKs are empty.  In this 
+case you will have to use the wantarray context in order to create those 
+values.
+
+=cut
+
+sub populate {
+  my $self = 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;
+    foreach my $item (@$data) {
+      push(@created, $self->create($item));
     }
+    return @created;
   } else {
-    $self->throw_exception(
-      "Can't delete on resultset with condition unless hash or array");
-  }
+    my ($first, @rest) = @$data;
 
-  $self->result_source->storage->delete($self->result_source->from, $del);
-  return 1;
+    my @names = grep {!ref $first->{$_}} keys %$first;
+    my @rels = grep { $self->result_source->has_relationship($_) } keys %$first;
+    my @pks = $self->result_source->primary_columns;  
+
+    ## do the belongs_to relationships  
+    foreach my $index (0..$#$data) {
+      if( grep { !defined $data->[$index]->{$_} } @pks ) {
+        my @ret = $self->populate($data);
+        return;
+      }
+    
+      foreach my $rel (@rels) {
+        next unless $data->[$index]->{$rel} && ref $data->[$index]->{$rel} eq "HASH";
+        my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
+        my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
+        my $related = $result->result_source->resolve_condition(
+          $result->result_source->relationship_info($reverse)->{cond},
+          $self,        
+          $result,        
+        );
+
+        delete $data->[$index]->{$rel};
+        $data->[$index] = {%{$data->[$index]}, %$related};
+      
+        push @names, keys %$related if $index == 0;
+      }
+    }
+
+    ## do bulk insert on current row
+    my @values = map { [ @$_{@names} ] } @$data;
+
+    $self->result_source->storage->insert_bulk(
+      $self->result_source, 
+      \@names, 
+      \@values,
+    );
+
+    ## do the has_many relationships
+    foreach my $item (@$data) {
+
+      foreach my $rel (@rels) {
+        next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
+
+        my $parent = $self->find(map {{$_=>$item->{$_}} } @pks) 
+     || $self->throw_exception('Cannot find the relating object.');
+     
+        my $child = $parent->$rel;
+    
+        my $related = $child->result_source->resolve_condition(
+          $parent->result_source->relationship_info($rel)->{cond},
+          $child,
+          $parent,
+        );
+
+        my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
+        my @populate = map { {%$_, %$related} } @rows_to_add;
+
+        $child->populate( \@populate );
+      }
+    }
+  }
 }
 
-=head2 delete_all
+=head2 _normalize_populate_args ($args)
 
-Fetches all objects and deletes them one at a time.  Note that C<delete_all>
-will run cascade triggers while L</delete> will not.
+Private method used by L</populate> to normalize its incoming arguments.  Factored
+out in case you want to subclass and accept new argument structures to the
+L</populate> method.
 
 =cut
 
-sub delete_all {
-  my ($self) = @_;
-  $_->delete for $self->all;
-  return 1;
+sub _normalize_populate_args {
+  my ($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
 
-Returns a L<Data::Page> object for the current resultset. Only makes
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $pager
+
+=back
+
+Return Value a L<Data::Page> object for the current resultset. Only makes
 sense for queries with a C<page> attribute.
 
 =cut
@@ -719,32 +1641,50 @@ sense for queries with a C<page> attribute.
 sub pager {
   my ($self) = @_;
   my $attrs = $self->{attrs};
-  $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page};
+  $self->throw_exception("Can't create pager for non-paged rs")
+    unless $self->{attrs}{page};
   $attrs->{rows} ||= 10;
   return $self->{pager} ||= Data::Page->new(
-    $self->_count, $attrs->{rows}, $self->{page});
+    $self->_count, $attrs->{rows}, $self->{attrs}{page});
 }
 
 =head2 page
 
-=head3 Arguments: ($page_num)
+=over 4
+
+=item Arguments: $page_number
 
-Returns a new resultset for the specified page.
+=item Return Value: $rs
+
+=back
+
+Returns a resultset for the $page_number page of the resultset on which page
+is called, where each page contains a number of rows equal to the 'rows'
+attribute set on the resultset (10 by default).
 
 =cut
 
 sub page {
   my ($self, $page) = @_;
-  my $attrs = { %{$self->{attrs}} };
-  $attrs->{page} = $page;
-  return (ref $self)->new($self->result_source, $attrs);
+  return (ref $self)->new($self->result_source, { %{$self->{attrs}}, page => $page });
 }
 
 =head2 new_result
 
-=head3 Arguments: (\%vals)
+=over 4
+
+=item Arguments: \%vals
+
+=item Return Value: $rowobject
 
-Creates a result in the resultset's result class.
+=back
+
+Creates a new row object in the resultset's result class and returns
+it. The row is not inserted into the database at this point, call
+L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
+will tell you whether the row object has been inserted or not.
+
+Passes the hashref of input on to L<DBIx::Class::Row/new>.
 
 =cut
 
@@ -752,259 +1692,942 @@ 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 $self->{cond} eq 'HASH'));
-  my %new = %$values;
+
+  my %new;
   my $alias = $self->{attrs}{alias};
-  foreach my $key (keys %{$self->{cond}||{}}) {
-    $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/);
+
+  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) },
+    -source_handle => $self->_source_handle,
+    -result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
+  );
+
+  return $self->result_class->new(\%new);
+}
+
+# _is_deterministic_value
+#
+# Make an effor to strip non-deterministic values from the condition, 
+# to make sure new_result chokes less
+
+sub _is_deterministic_value {
+  my $self = shift;
+  my $value = shift;
+  my $ref_type = ref $value;
+  return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
+  return 1 if Scalar::Util::blessed($value);
+  return 0;
+}
+
+# _collapse_cond
+#
+# Recursively collapse the condition.
+
+sub _collapse_cond {
+  my ($self, $cond, $collapsed) = @_;
+
+  $collapsed ||= {};
+
+  if (ref $cond eq 'ARRAY') {
+    foreach my $subcond (@$cond) {
+      next unless ref $subcond;  # -or
+#      warn "ARRAY: " . Dumper $subcond;
+      $collapsed = $self->_collapse_cond($subcond, $collapsed);
+    }
   }
-  my $obj = $self->result_class->new(\%new);
-  $obj->result_source($self->result_source) if $obj->can('result_source');
-  return $obj;
+  elsif (ref $cond eq 'HASH') {
+    if (keys %$cond and (keys %$cond)[0] eq '-and') {
+      foreach my $subcond (@{$cond->{-and}}) {
+#        warn "HASH: " . Dumper $subcond;
+        $collapsed = $self->_collapse_cond($subcond, $collapsed);
+      }
+    }
+    else {
+#      warn "LEAF: " . Dumper $cond;
+      foreach my $col (keys %$cond) {
+        my $value = $cond->{$col};
+        $collapsed->{$col} = $value;
+      }
+    }
+  }
+
+  return $collapsed;
+}
+
+# _remove_alias
+#
+# Remove the specified alias from the specified query hash. A copy is made so
+# the original query is not modified.
+
+sub _remove_alias {
+  my ($self, $query, $alias) = @_;
+
+  my %orig = %{ $query || {} };
+  my %unaliased;
+
+  foreach my $key (keys %orig) {
+    if ($key !~ /\./) {
+      $unaliased{$key} = $orig{$key};
+      next;
+    }
+    $unaliased{$1} = $orig{$key}
+      if $key =~ m/^(?:\Q$alias\E\.)?([^.]+)$/;
+  }
+
+  return \%unaliased;
+}
+
+=head2 as_query
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \[ $sql, @bind ]
+
+=back
+
+Returns the SQL query and bind vars associated with the invocant.
+
+This is generally used as the RHS for a subquery.
+
+=cut
+
+sub as_query { return shift->cursor->as_query(@_) }
+
+=head2 find_or_new
+
+=over 4
+
+=item Arguments: \%vals, \%attrs?
+
+=item Return Value: $rowobject
+
+=back
+
+  my $artist = $schema->resultset('Artist')->find_or_new(
+    { artist => 'fred' }, { key => 'artists' });
+
+  $cd->cd_to_producer->find_or_new({ producer => $producer },
+                                   { key => 'primary });
+
+Find an existing record from this resultset, based on its primary
+key, or a unique constraint. If none exists, instantiate a new result
+object and return it. The object will not be saved into your storage
+until you call L<DBIx::Class::Row/insert> on it.
+
+You most likely want this method when looking for existing rows using
+a unique constraint that is not the primary key, or looking for
+related rows.
+
+If you want objects to be saved immediately, use L</find_or_create> instead.
+
+B<Note>: C<find_or_new> is probably not what you want when creating a
+new row in a table that uses primary keys supplied by the
+database. Passing in a primary key column with a value of I<undef>
+will cause L</find> to attempt to search for a row with a value of
+I<NULL>.
+
+=cut
+
+sub find_or_new {
+  my $self     = shift;
+  my $attrs    = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+  my $hash     = ref $_[0] eq 'HASH' ? shift : {@_};
+  my $exists   = $self->find($hash, $attrs);
+  return defined $exists ? $exists : $self->new_result($hash);
 }
 
-=head2 create
+=head2 create
+
+=over 4
+
+=item Arguments: \%vals
+
+=item Return Value: a L<DBIx::Class::Row> $object
+
+=back
+
+Attempt to create a single new row or a row with multiple related rows
+in the table represented by the resultset (and related tables). This
+will not check for duplicate rows before inserting, use
+L</find_or_create> to do that.
+
+To create one row for this resultset, pass a hashref of key/value
+pairs representing the columns of the table and the values you wish to
+store. If the appropriate relationships are set up, foreign key fields
+can also be passed an object representing the foreign row, and the
+value will be set to its primary key.
+
+To create related objects, pass a hashref for the value if the related
+item is a foreign key relationship (L<DBIx::Class::Relationship/belongs_to>),
+and use the name of the relationship as the key. (NOT the name of the field,
+necessarily). For C<has_many> and C<has_one> relationships, pass an arrayref
+of hashrefs containing the data for each of the rows to create in the foreign
+tables, again using the relationship name as the key.
+
+Instead of hashrefs of plain related data (key/value pairs), you may
+also pass new or inserted objects. New objects (not inserted yet, see
+L</new>), will be inserted into their appropriate tables.
+
+Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
+
+Example of creating a new row.
+
+  $person_rs->create({
+    name=>"Some Person",
+    email=>"somebody@someplace.com"
+  });
+  
+Example of creating a new row and also creating rows in a related C<has_many>
+or C<has_one> resultset.  Note Arrayref.
+
+  $artist_rs->create(
+     { artistid => 4, name => 'Manufactured Crap', cds => [ 
+        { title => 'My First CD', year => 2006 },
+        { title => 'Yet More Tweeny-Pop crap', year => 2007 },
+      ],
+     },
+  );
+
+Example of creating a new row and also creating a row in a related
+C<belongs_to>resultset. Note Hashref.
+
+  $cd_rs->create({
+    title=>"Music for Silly Walks",
+    year=>2000,
+    artist => {
+      name=>"Silly Musician",
+    }
+  });
+
+=cut
+
+sub create {
+  my ($self, $attrs) = @_;
+  $self->throw_exception( "create needs a hashref" )
+    unless ref $attrs eq 'HASH';
+  return $self->new_result($attrs)->insert;
+}
+
+=head2 find_or_create
+
+=over 4
+
+=item Arguments: \%vals, \%attrs?
+
+=item Return Value: $rowobject
+
+=back
+
+  $cd->cd_to_producer->find_or_create({ producer => $producer },
+                                      { key => 'primary });
+
+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({
+    cdid   => 5,
+    artist => 'Massive Attack',
+    title  => 'Mezzanine',
+    year   => 2005,
+  });
+
+Also takes an optional C<key> attribute, to search by a specific key or unique
+constraint. For example:
+
+  my $cd = $schema->resultset('CD')->find_or_create(
+    {
+      artist => 'Massive Attack',
+      title  => 'Mezzanine',
+    },
+    { key => 'cd_artist_title' }
+  );
+
+B<Note>: Because find_or_create() reads from the database and then
+possibly inserts based on the result, this method is subject to a race
+condition. Another process could create a record in the table after
+the find has completed and before the create has started. To avoid
+this problem, use find_or_create() inside a transaction.
+
+B<Note>: C<find_or_create> is probably not what you want when creating
+a new row in a table that uses primary keys supplied by the
+database. Passing in a primary key column with a value of I<undef>
+will cause L</find> to attempt to search for a row with a value of
+I<NULL>.
+
+See also L</find> and L</update_or_create>. For information on how to declare
+unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+
+=cut
+
+sub find_or_create {
+  my $self     = shift;
+  my $attrs    = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+  my $hash     = ref $_[0] eq 'HASH' ? shift : {@_};
+  my $exists   = $self->find($hash, $attrs);
+  return defined $exists ? $exists : $self->create($hash);
+}
+
+=head2 update_or_create
+
+=over 4
+
+=item Arguments: \%col_values, { key => $unique_constraint }?
+
+=item Return Value: $rowobject
+
+=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.
+
+Takes an optional C<key> attribute to search on a specific unique constraint.
+For example:
+
+  # In your application
+  my $cd = $schema->resultset('CD')->update_or_create(
+    {
+      artist => 'Massive Attack',
+      title  => 'Mezzanine',
+      year   => 1998,
+    },
+    { key => 'cd_artist_title' }
+  );
+
+  $cd->cd_to_producer->update_or_create({ 
+    producer => $producer, 
+    name => 'harry',
+  }, { 
+    key => 'primary,
+  });
+
+
+If no C<key> is specified, it searches on all unique constraints defined on the
+source, including the primary key.
+
+If the C<key> is specified as C<primary>, it searches only on the primary key.
+
+See also L</find> and L</find_or_create>. For information on how to declare
+unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+
+B<Note>: C<update_or_create> is probably not what you want when
+looking for a row in a table that uses primary keys supplied by the
+database, unless you actually have a key value. Passing in a primary
+key column with a value of I<undef> will cause L</find> to attempt to
+search for a row with a value of I<NULL>.
+
+=cut
+
+sub update_or_create {
+  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 $self->create($cond);
+}
+
+=head2 get_cache
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: \@cache_objects?
+
+=back
+
+Gets the contents of the cache for the resultset, if the cache is set.
+
+The cache is populated either by using the L</prefetch> attribute to
+L</search> or by calling L</set_cache>.
+
+=cut
+
+sub get_cache {
+  shift->{all_cache};
+}
+
+=head2 set_cache
+
+=over 4
+
+=item Arguments: \@cache_objects
+
+=item Return Value: \@cache_objects
+
+=back
+
+Sets the contents of the cache for the resultset. Expects an arrayref
+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</prefetch> attribute to L</search>.
+
+=cut
+
+sub set_cache {
+  my ( $self, $data ) = @_;
+  $self->throw_exception("set_cache requires an arrayref")
+      if defined($data) && (ref $data ne 'ARRAY');
+  $self->{all_cache} = $data;
+}
+
+=head2 clear_cache
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: []
+
+=back
+
+Clears the cache for the resultset.
+
+=cut
+
+sub clear_cache {
+  shift->set_cache(undef);
+}
+
+=head2 related_resultset
+
+=over 4
+
+=item Arguments: $relationship_name
+
+=item Return Value: $resultset
+
+=back
+
+Returns a related resultset for the supplied relationship name.
+
+  $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
+
+=cut
+
+sub related_resultset {
+  my ($self, $rel) = @_;
+
+  $self->{related_resultsets} ||= {};
+  return $self->{related_resultsets}{$rel} ||= do {
+    my $rel_obj = $self->result_source->relationship_info($rel);
+
+    $self->throw_exception(
+      "search_related: result source '" . $self->result_source->source_name .
+        "' has no such relationship $rel")
+      unless $rel_obj;
+    
+    my ($from,$seen) = $self->_resolve_from($rel);
+
+    my $join_count = $seen->{$rel};
+    my $alias = ($join_count > 1 ? join('_', $rel, $join_count) : $rel);
+
+    #XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
+    my %attrs = %{$self->{attrs}||{}};
+    delete @attrs{qw(result_class alias)};
+
+    my $new_cache;
+
+    if (my $cache = $self->get_cache) {
+      if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
+        $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
+                        @$cache ];
+      }
+    }
+
+    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
 
-=head3 Arguments: (\%vals)
+=item Return Value: $source_alias
 
-Inserts a record into the resultset and returns the object.
+=back
 
-Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
+Returns the current table alias for the result source this resultset is built
+on, that will be used in the SQL query. Usually it is C<me>.
 
-=cut
+Currently the source alias that refers to the result set returned by a
+L</search>/L</find> family method depends on how you got to the resultset: it's
+C<me> by default, but eg. L</search_related> aliases it to the related result
+source name (and keeps C<me> referring to the original result set). The long
+term goal is to make L<DBIx::Class> always alias the current resultset as C<me>
+(and make this method unnecessary).
 
-sub create {
-  my ($self, $attrs) = @_;
-  $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH';
-  return $self->new_result($attrs)->insert;
-}
+Thus it's currently necessary to use this method in predefined queries (see
+L<DBIx::Class::Manual::Cookbook/Predefined searches>) when referring to the
+source alias of the current result set:
 
-=head2 find_or_create
+  # in a result set class
+  sub modified_by {
+    my ($self, $user) = @_;
 
-=head3 Arguments: (\%vals, \%attrs?)
+    my $me = $self->current_source_alias;
 
-  $class->find_or_create({ key => $val, ... });
+    return $self->search(
+      "$me.modified" => $user->id,
+    );
+  }
 
-Searches for a record matching the search condition; if it doesn't find one,
-creates one and returns that instead.
+=cut
 
-  my $cd = $schema->resultset('CD')->find_or_create({
-    cdid   => 5,
-    artist => 'Massive Attack',
-    title  => 'Mezzanine',
-    year   => 2005,
-  });
+sub current_source_alias {
+  my ($self) = @_;
 
-Also takes an optional C<key> attribute, to search by a specific key or unique
-constraint. For example:
+  return ($self->{attrs} || {})->{alias} || 'me';
+}
 
-  my $cd = $schema->resultset('CD')->find_or_create(
-    {
-      artist => 'Massive Attack',
-      title  => 'Mezzanine',
-    },
-    { key => 'artist_title' }
-  );
+sub _resolve_from {
+  my ($self, $extra_join) = @_;
+  my $source = $self->result_source;
+  my $attrs = $self->{attrs};
+  
+  my $from = $attrs->{from}
+    || [ { $attrs->{alias} => $source->from } ];
+    
+  my $seen = { %{$attrs->{seen_join}||{}} };
 
-See also L</find> and L</update_or_create>.
+  my $join = ($attrs->{join}
+               ? [ $attrs->{join}, $extra_join ]
+               : $extra_join);
 
-=cut
+  # we need to take the prefetch the attrs into account before we 
+  # ->resolve_join as otherwise they get lost - captainL
+  my $merged = $self->_merge_attr( $join, $attrs->{prefetch} );
 
-sub find_or_create {
-  my $self     = shift;
-  my $attrs    = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
-  my $hash     = ref $_[0] eq 'HASH' ? shift : {@_};
-  my $exists   = $self->find($hash, $attrs);
-  return defined $exists ? $exists : $self->create($hash);
-}
+  $from = [
+    @$from,
+    ($join ? $source->resolve_join($merged, $attrs->{alias}, $seen) : ()),
+  ];
 
-=head2 update_or_create
+  return ($from,$seen);
+}
 
-  $class->update_or_create({ key => $val, ... });
+sub _resolved_attrs {
+  my $self = shift;
+  return $self->{_attrs} if $self->{_attrs};
+
+  my $attrs  = { %{ $self->{attrs} || {} } };
+  my $source = $self->result_source;
+  my $alias  = $attrs->{alias};
+
+  $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
+  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} || $source->columns );
+  }
+  # add the additional columns on
+  foreach ( 'include_columns', '+columns' ) {
+      push @colbits, map {
+          ( ref($_) eq 'HASH' )
+            ? $_
+            : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
+      } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
+  }
 
-First, search 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, update it with the other given column values.  Otherwise, create a new
-row.
+  # 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} } ]
+    );
+  }
+  else {
 
-Takes an optional C<key> attribute to search on a specific unique constraint.
-For example:
+    # otherwise we intialise select & as to empty
+    $attrs->{select} = [];
+    $attrs->{as}     = [];
+  }
 
-  # In your application
-  my $cd = $schema->resultset('CD')->update_or_create(
-    {
-      artist => 'Massive Attack',
-      title  => 'Mezzanine',
-      year   => 1998,
-    },
-    { key => 'artist_title' }
-  );
+  # now add colbits to select/as
+  push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
+  push( @{ $attrs->{as} },     map { keys( %{$_} ) } @colbits );
 
-If no C<key> is specified, it searches on all unique constraints defined on the
-source, including the primary key.
+  my $adds;
+  if ( $adds = delete $attrs->{'+select'} ) {
+    $adds = [$adds] unless ref $adds eq 'ARRAY';
+    push(
+      @{ $attrs->{select} },
+      map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
+    );
+  }
+  if ( $adds = delete $attrs->{'+as'} ) {
+    $adds = [$adds] unless ref $adds eq 'ARRAY';
+    push( @{ $attrs->{as} }, @$adds );
+  }
 
-If the C<key> is specified as C<primary>, search only on the primary key.
+  $attrs->{from} ||= [ { $self->{attrs}{alias} => $source->from } ];
 
-See also L</find> and L</find_or_create>.
+  if ( exists $attrs->{join} || exists $attrs->{prefetch} ) {
+    my $join = delete $attrs->{join} || {};
 
-=cut
+    if ( defined $attrs->{prefetch} ) {
+      $join = $self->_merge_attr( $join, $attrs->{prefetch} );
 
-sub update_or_create {
-  my $self = shift;
-  my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
-  my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
+    }
 
-  my %unique_constraints = $self->result_source->unique_constraints;
-  my @constraint_names   = (exists $attrs->{key}
-                            ? ($attrs->{key})
-                            : keys %unique_constraints);
+    $attrs->{from} =    # have to copy here to avoid corrupting the original
+      [
+      @{ $attrs->{from} },
+      $source->resolve_join(
+        $join, $alias, { %{ $attrs->{seen_join} || {} } }
+      )
+      ];
 
-  my @unique_hashes;
-  foreach my $name (@constraint_names) {
-    my @unique_cols = @{ $unique_constraints{$name} };
-    my %unique_hash =
-      map  { $_ => $hash->{$_} }
-      grep { exists $hash->{$_} }
-      @unique_cols;
+  }
 
-    push @unique_hashes, \%unique_hash
-      if (scalar keys %unique_hash == scalar @unique_cols);
+  $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} = [];
   }
 
-  if (@unique_hashes) {
-    my $row = $self->single(\@unique_hashes);
-    if (defined $row) {
-      $row->set_columns($hash);
-      $row->update;
-      return $row;
+  my $collapse = $attrs->{collapse} || {};
+  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) ) {
+
+      # 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 );
     }
+    push( @{ $attrs->{order_by} }, @pre_order );
   }
+  $attrs->{collapse} = $collapse;
 
-  return $self->create($hash);
-}
+  if ( $attrs->{page} ) {
+    $attrs->{offset} ||= 0;
+    $attrs->{offset} += ( $attrs->{rows} * ( $attrs->{page} - 1 ) );
+  }
 
-=head2 get_cache
+  return $self->{_attrs} = $attrs;
+}
 
-Gets the contents of the cache for the resultset.
+sub _rollout_attr {
+  my ($self, $attr) = @_;
+  
+  if (ref $attr eq 'HASH') {
+    return $self->_rollout_hash($attr);
+  } elsif (ref $attr eq 'ARRAY') {
+    return $self->_rollout_array($attr);
+  } else {
+    return [$attr];
+  }
+}
 
-=cut
+sub _rollout_array {
+  my ($self, $attr) = @_;
 
-sub get_cache {
-  shift->{all_cache} || [];
+  my @rolled_array;
+  foreach my $element (@{$attr}) {
+    if (ref $element eq 'HASH') {
+      push( @rolled_array, @{ $self->_rollout_hash( $element ) } );
+    } elsif (ref $element eq 'ARRAY') {
+      #  XXX - should probably recurse here
+      push( @rolled_array, @{$self->_rollout_array($element)} );
+    } else {
+      push( @rolled_array, $element );
+    }
+  }
+  return \@rolled_array;
 }
 
-=head2 set_cache
+sub _rollout_hash {
+  my ($self, $attr) = @_;
 
-Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset.
+  my @rolled_array;
+  foreach my $key (keys %{$attr}) {
+    push( @rolled_array, { $key => $attr->{$key} } );
+  }
+  return \@rolled_array;
+}
 
-=cut
+sub _calculate_score {
+  my ($self, $a, $b) = @_;
 
-sub set_cache {
-  my ( $self, $data ) = @_;
-  $self->throw_exception("set_cache requires an arrayref")
-    if ref $data ne 'ARRAY';
-  my $result_class = $self->result_class;
-  foreach( @$data ) {
-    $self->throw_exception("cannot cache object of type '$_', expected '$result_class'")
-      if ref $_ ne $result_class;
+  if (ref $b eq 'HASH') {
+    my ($b_key) = keys %{$b};
+    if (ref $a eq 'HASH') {
+      my ($a_key) = keys %{$a};
+      if ($a_key eq $b_key) {
+        return (1 + $self->_calculate_score( $a->{$a_key}, $b->{$b_key} ));
+      } else {
+        return 0;
+      }
+    } else {
+      return ($a eq $b_key) ? 1 : 0;
+    }       
+  } else {
+    if (ref $a eq 'HASH') {
+      my ($a_key) = keys %{$a};
+      return ($b eq $a_key) ? 1 : 0;
+    } else {
+      return ($b eq $a) ? 1 : 0;
+    }
   }
-  $self->{all_cache} = $data;
 }
 
-=head2 clear_cache
+sub _merge_attr {
+  my ($self, $orig, $import) = @_;
 
-Clears the cache for the resultset.
+  return $import unless defined($orig);
+  return $orig unless defined($import);
+  
+  $orig = $self->_rollout_attr($orig);
+  $import = $self->_rollout_attr($import);
+
+  my $seen_keys;
+  foreach my $import_element ( @{$import} ) {
+    # find best candidate from $orig to merge $b_element into
+    my $best_candidate = { position => undef, score => 0 }; my $position = 0;
+    foreach my $orig_element ( @{$orig} ) {
+      my $score = $self->_calculate_score( $orig_element, $import_element );
+      if ($score > $best_candidate->{score}) {
+        $best_candidate->{position} = $position;
+        $best_candidate->{score} = $score;
+      }
+      $position++;
+    }
+    my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
 
-=cut
+    if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
+      push( @{$orig}, $import_element );
+    } else {
+      my $orig_best = $orig->[$best_candidate->{position}];
+      # merge orig_best and b_element together and replace original with merged
+      if (ref $orig_best ne 'HASH') {
+        $orig->[$best_candidate->{position}] = $import_element;
+      } elsif (ref $import_element eq 'HASH') {
+        my ($key) = keys %{$orig_best};
+        $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
+      }
+    }
+    $seen_keys->{$import_key} = 1; # don't merge the same key twice
+  }
 
-sub clear_cache {
-  shift->set_cache([]);
+  return $orig;
 }
 
-=head2 related_resultset
-
-Returns a related resultset for the supplied relationship name.
-
-  $artist_rs = $schema->resultset('CD')->related_resultset('Artist');
-
-=cut
+sub result_source {
+    my $self = shift;
 
-sub related_resultset {
-  my ( $self, $rel, @rest ) = @_;
-  $self->{related_resultsets} ||= {};
-  return $self->{related_resultsets}{$rel} ||= do {
-      #warn "fetching related resultset for rel '$rel'";
-      my $rel_obj = $self->result_source->relationship_info($rel);
-      $self->throw_exception(
-        "search_related: result source '" . $self->result_source->name .
-        "' has no such relationship ${rel}")
-        unless $rel_obj; #die Dumper $self->{attrs};
-
-      my $rs = $self->search(undef, { join => $rel });
-      my $alias = defined $rs->{attrs}{seen_join}{$rel}
-                    && $rs->{attrs}{seen_join}{$rel} > 1
-                  ? join('_', $rel, $rs->{attrs}{seen_join}{$rel})
-                  : $rel;
-
-      $self->result_source->schema->resultset($rel_obj->{class}
-           )->search( undef,
-             { %{$rs->{attrs}},
-               alias => $alias,
-               select => undef,
-               as => undef }
-           )->search(@rest);      
-  };
+    if (@_) {
+        $self->_source_handle($_[0]->handle);
+    } else {
+        $self->_source_handle->resolve;
+    }
 }
 
 =head2 throw_exception
 
-See Schema's throw_exception
+See L<DBIx::Class::Schema/throw_exception> for details.
 
 =cut
 
 sub throw_exception {
   my $self=shift;
-  $self->result_source->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</search>, L</search_rs>, L</find>,
+L</count>.
+
+These are in no particular order:
 
 =head2 order_by
 
+=over 4
+
+=item Value: ($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<year DESC> for a
 descending order on the column `year'.
 
+Please note that if you have C<quote_char> enabled (see
+L<DBIx::Class::Storage::DBI/connect_info>) 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.)
+
+If your L<SQL::Abstract> version supports it (>=1.50), you can also use
+C<{-desc => 'year'}>, which takes care of the quoting for you. This is the
+recommended syntax.
+
 =head2 columns
 
-=head3 Arguments: (arrayref)
+=over 4
 
-Shortcut to request a particular set of columns to be retrieved.  Adds
-C<me.> onto the start of any column without a C<.> in it and sets C<select>
-from that, then auto-populates C<as> from C<select> as normal. (You may also
-use the C<cols> attribute, as in earlier versions of DBIC.)
+=item Value: \@columns
 
-=head2 include_columns
+=back
+
+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<as> value, and the value is used as the C<select>
+expression). Adds C<me.> onto the start of any column without a C<.> in
+it and sets C<select> from that, then auto-populates C<as> from
+C<select> as normal. (You may also use the C<cols> attribute, as in
+earlier versions of DBIC.)
+
+=head2 +columns
+
+=over 4
+
+=item Value: \@columns
 
-=head3 Arguments: (arrayref)
+=back
 
-Shortcut to include additional columns in the returned results - for example
+Indicates additional columns to be selected from storage. Works the same
+as L</columns> but adds columns to the selection. (You may also use the
+C<include_columns> attribute, as in earlier versions of DBIC). For
+example:-
 
   $schema->resultset('CD')->search(undef, {
-    include_columns => ['artist.name'],
+    '+columns' => ['artist.name'],
     join => ['artist']
   });
 
 would return all CDs and include a 'name' column to the information
-passed to object inflation
+passed to object inflation. Note that the 'artist' is the name of the
+column (or relationship) accessor, and 'name' is the name of the column
+accessor in the related table.
+
+=head2 include_columns
+
+=over 4
+
+=item Value: \@columns
+
+=back
+
+Deprecated.  Acts as a synonym for L</+columns> for backward compatibility.
 
 =head2 select
 
-=head3 Arguments: (arrayref)
+=over 4
+
+=item Value: \@select_columns
+
+=back
 
 Indicates which columns should be selected from the storage. You can use
 column names, or in the case of RDBMS back ends, function or stored procedure
@@ -1022,12 +2645,38 @@ When you use function/stored procedure names and do not supply an C<as>
 attribute, the column names returned are storage-dependent. E.g. MySQL would
 return a column named C<count(employeeid)> in the above example.
 
+=head2 +select
+
+=over 4
+
+Indicates additional columns to be selected from storage.  Works the same as
+L</select> but adds columns to the selection.
+
+=back
+
+=head2 +as
+
+=over 4
+
+Indicates additional column names for those added via L</+select>. See L</as>.
+
+=back
+
 =head2 as
 
-=head3 Arguments: (arrayref)
+=over 4
 
-Indicates column names for object inflation. This is used in conjunction with
-C<select>, usually when C<select> contains one or more function or stored
+=item Value: \@inflation_names
+
+=back
+
+Indicates column names for object inflation. That is, C<as>
+indicates the name that the column can be accessed as via the
+C<get_column> method (or via the object accessor, B<if one already
+exists>).  It has nothing to do with the SQL code C<SELECT foo AS bar>.
+
+The C<as> attribute is used in conjunction with C<select>,
+usually when C<select> contains one or more function or stored
 procedure names:
 
   $rs = $schema->resultset('Employee')->search(undef, {
@@ -1054,8 +2703,24 @@ use C<get_column> instead:
 You can create your own accessors if required - see
 L<DBIx::Class::Manual::Cookbook> for details.
 
+Please note: This will NOT insert an C<AS employee_count> into the SQL
+statement produced, it is used for internal access only. Thus
+attempting to use the accessor in an C<order_by> clause or similar
+will fail miserably.
+
+To get around this limitation, you can supply literal SQL to your
+C<select> attibute that contains the C<AS alias> text, eg:
+
+  select => [\'myfield AS alias']
+
 =head2 join
 
+=over 4
+
+=item Value: ($rel_name | \@rel_names | \%rel_names)
+
+=back
+
 Contains a list of relationships that should be joined for this query.  For
 example:
 
@@ -1085,6 +2750,19 @@ For example:
     }
   );
 
+You need to use the relationship (not the table) name in  conditions, 
+because they are aliased as such. The current table is aliased as "me", so 
+you need to use me.column_name in order to avoid ambiguity. For example:
+
+  # Get CDs from 1984 with a 'Foo' track 
+  my $rs = $schema->resultset('CD')->search(
+    { 
+      'me.year' => 1984,
+      'tracks.name' => 'Foo'
+    },
+    { join => 'tracks' }
+  );
+  
 If the same join is supplied twice, it will be aliased to <rel>_2 (and
 similarly for a third time). For e.g.
 
@@ -1101,14 +2779,21 @@ to Earth' and a cd with title 'Popular'.
 If you want to fetch related objects from other tables as well, see C<prefetch>
 below.
 
+For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
+
 =head2 prefetch
 
-=head3 Arguments: arrayref/hashref
+=over 4
+
+=item Value: ($rel_name | \@rel_names | \%rel_names)
 
-Contains one or more relationships that should be fetched along with the main 
-query (when they are accessed afterwards they will have already been
-"prefetched").  This is useful for when you know you will need the related
-objects, because it saves at least one query:
+=back
+
+Contains one or more relationships that should be fetched along with
+the main query (when they are accessed afterwards the data will
+already be available, without extra queries to the database).  This is
+useful for when you know you will need the related objects, because it
+saves at least one query:
 
   my $rs = $schema->resultset('Tag')->search(
     undef,
@@ -1130,38 +2815,174 @@ C<cd> or C<artist> relationships, which saves us two SQL statements in this
 case.
 
 Simple prefetches will be joined automatically, so there is no need
-for a C<join> attribute in the above search. If you're prefetching to
-depth (e.g. { cd => { artist => 'label' } or similar), you'll need to
-specify the join as well.
+for a C<join> attribute in the above search. 
 
 C<prefetch> can be used with the following relationship types: C<belongs_to>,
 C<has_one> (or if you're using C<add_relationship>, any relationship declared
-with an accessor type of 'single' or 'filter').
+with an accessor type of 'single' or 'filter'). A more complex example that
+prefetches an artists cds, the tracks on those cds, and the tags associted 
+with that artist is given below (assuming many-to-many from artists to tags):
+
+ my $rs = $schema->resultset('Artist')->search(
+   undef,
+   {
+     prefetch => [
+       { cds => 'tracks' },
+       { artist_tags => 'tags' }
+     ]
+   }
+ );
+ 
+
+B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
+attributes will be ignored.
+
+=head2 page
+
+=over 4
+
+=item Value: $page
+
+=back
+
+Makes the resultset paged and specifies the page to retrieve. Effectively
+identical to creating a non-pages resultset and then calling ->page($page)
+on it.
+
+If L<rows> attribute is not specified it defualts to 10 rows per page.
+
+=head2 rows
+
+=over 4
+
+=item Value: $rows
+
+=back
+
+Specifes the maximum number of rows for direct retrieval or the number of
+rows per page if the page attribute or method is used.
+
+=head2 offset
+
+=over 4
+
+=item Value: $offset
+
+=back
+
+Specifies the (zero-based) row number for the  first row to be returned, or the
+of the first row of the first page if paging is used.
+
+=head2 group_by
+
+=over 4
+
+=item Value: \@columns
+
+=back
+
+A arrayref of columns to group by. Can include columns of joined tables.
+
+  group_by => [qw/ column1 column2 ... /]
+
+=head2 having
+
+=over 4
+
+=item Value: $condition
+
+=back
+
+HAVING is a select statement attribute that is applied between GROUP BY and
+ORDER BY. It is applied to the after the grouping calculations have been
+done.
+
+  having => { 'count(employee)' => { '>=', 100 } }
+
+=head2 distinct
+
+=over 4
+
+=item Value: (0 | 1)
+
+=back
+
+Set to 1 to group by all columns.
+
+=head2 where
+
+=over 4
+
+Adds to the WHERE clause.
+
+  # only return rows WHERE deleted IS NULL for all searches
+  __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
+
+Can be overridden by passing C<{ where => undef }> as an attribute
+to a resulset.
+
+=back
+
+=head2 cache
+
+Set to 1 to cache search results. This prevents extra SQL queries if you
+revisit rows in your ResultSet:
+
+  my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } );
+
+  while( my $artist = $resultset->next ) {
+    ... do stuff ...
+  }
+
+  $rs->first; # without cache, this would issue a query
+
+By default, searches are not cached.
+
+For more examples of using these attributes, see
+L<DBIx::Class::Manual::Cookbook>.
 
 =head2 from
 
-=head3 Arguments: (arrayref)
+=over 4
+
+=item Value: \@from_clause
+
+=back
 
 The C<from> attribute gives you manual control over the C<FROM> clause of SQL
 statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN>
 clauses.
 
 NOTE: Use this on your own risk.  This allows you to shoot off your foot!
+
 C<join> will usually do what you need and it is strongly recommended that you
 avoid using C<from> unless you cannot achieve the desired result using C<join>.
+And we really do mean "cannot", not just tried and failed. Attempting to use
+this because you're having problems with C<join> is like trying to use x86
+ASM because you've got a syntax error in your C. Trust us on this.
 
-In simple terms, C<from> works as follows:
+Now, if you're still really, really sure you need to use this (and if you're
+not 100% sure, ask the mailing list first), here's an explanation of how this
+works.
 
+The syntax is as follows -
+
+  [
+    { <alias1> => <table1> },
     [
-        { <alias> => <table>, -join-type => 'inner|left|right' }
-        [] # nested JOIN (optional)
-        { <table.column> = <foreign_table.foreign_key> }
-    ]
+      { <alias2> => <table2>, -join_type => 'inner|left|right' },
+      [], # nested JOIN (optional)
+      { <table1.column1> => <table2.column2>, ... (more conditions) },
+    ],
+    # More of the above [ ] may follow for additional joins
+  ]
 
-    JOIN
-        <alias> <table>
-        [JOIN ...]
-    ON <table.column> = <foreign_table.foreign_key>
+  <table1> <alias1>
+  JOIN
+    <table2> <alias2>
+    [JOIN ...]
+  ON <table1.column1> = <table2.column2>
+  <more joins may follow>
 
 An easy way to follow the examples below is to remember the following:
 
@@ -1216,7 +3037,7 @@ with a father in the person table, we could explicitly use C<INNER JOIN>:
             from => [
                 { child => 'person' },
                 [
-                    { father => 'person', -join-type => 'inner' },
+                    { father => 'person', -join_type => 'inner' },
                     { 'father.id' => 'child.father_id' }
                 ],
             ]
@@ -1227,33 +3048,68 @@ with a father in the person table, we could explicitly use C<INNER JOIN>:
     # SELECT child.* FROM person child
     # INNER JOIN person father ON child.father_id = father.id
 
-=head2 page
-
-For a paged resultset, specifies which page to retrieve.  Leave unset
-for an unpaged resultset.
-
-=head2 rows
-
-For a paged resultset, how many rows per page:
-
-  rows => 10
-
-Can also be used to simulate an SQL C<LIMIT>.
+If you need to express really complex joins or you need a subselect, you
+can supply literal SQL to C<from> via a scalar reference. In this case
+the contents of the scalar will replace the table name asscoiated with the
+resultsource.
+
+WARNING: This technique might very well not work as expected on chained
+searches - you have been warned.
+
+    # Assuming the Event resultsource is defined as:
+
+        MySchema::Event->add_columns (
+            sequence => {
+                data_type => 'INT',
+                is_auto_increment => 1,
+            },
+            location => {
+                data_type => 'INT',
+            },
+            type => {
+                data_type => 'INT',
+            },
+        );
+        MySchema::Event->set_primary_key ('sequence');
+
+    # This will get back the latest event for every location. The column
+    # selector is still provided by DBIC, all we do is add a JOIN/WHERE
+    # combo to limit the resultset
+
+    $rs = $schema->resultset('Event');
+    $table = $rs->result_source->name;
+    $latest = $rs->search (
+        undef,
+        { from => \ " 
+            (SELECT e1.* FROM $table e1 
+                JOIN $table e2 
+                    ON e1.location = e2.location 
+                    AND e1.sequence < e2.sequence 
+                WHERE e2.sequence is NULL 
+            ) me",
+        },
+    );
 
-=head2 group_by
+    # Equivalent SQL (with the DBIC chunks added):
 
-=head3 Arguments: (arrayref)
+    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;
 
-A arrayref of columns to group by. Can include columns of joined tables.
+=head2 for
 
-  group_by => [qw/ column1 column2 ... /]
+=over 4
 
-=head2 distinct
+=item Value: ( 'update' | 'shared' )
 
-Set to 1 to group by all columns.
+=back
 
-For more examples of using these attributes, see
-L<DBIx::Class::Manual::Cookbook>.
+Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
+... FOR SHARED.
 
 =cut