X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FRow.pm;h=a397cebf7a41a4b8b597d0cedea4a5f929d5d6c5;hb=48580715af3072905f2c71dc27e7f70f21a11338;hp=377e5e849e088c3063f30ae43b20615fe26a601e;hpb=1bc193ac4c3bb934d1877e49bf7c465fc82815d6;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Row.pm b/lib/DBIx/Class/Row.pm
index 377e5e8..a397ceb 100644
--- a/lib/DBIx/Class/Row.pm
+++ b/lib/DBIx/Class/Row.pm
@@ -4,9 +4,20 @@ use strict;
 use warnings;
 
 use base qw/DBIx::Class/;
-use Carp::Clan qw/^DBIx::Class/;
+
+use DBIx::Class::Exception;
 use Scalar::Util ();
-use Scope::Guard;
+
+###
+### Internal method
+### Do not use
+###
+BEGIN {
+  *MULTICREATE_DEBUG =
+    $ENV{DBIC_MULTICREATE_DEBUG}
+      ? sub () { 1 }
+      : sub () { 0 };
+}
 
 __PACKAGE__->mk_group_accessors('simple' => qw/_source_handle/);
 
@@ -21,13 +32,42 @@ DBIx::Class::Row - Basic row methods
 This class is responsible for defining and doing basic operations on rows
 derived from L<DBIx::Class::ResultSource> objects.
 
+Row objects are returned from L<DBIx::Class::ResultSet>s using the
+L<create|DBIx::Class::ResultSet/create>, L<find|DBIx::Class::ResultSet/find>,
+L<next|DBIx::Class::ResultSet/next> and L<all|DBIx::Class::ResultSet/all> methods,
+as well as invocations of 'single' (
+L<belongs_to|DBIx::Class::Relationship/belongs_to>,
+L<has_one|DBIx::Class::Relationship/has_one> or
+L<might_have|DBIx::Class::Relationship/might_have>)
+relationship accessors of L<DBIx::Class::Row> objects.
+
 =head1 METHODS
 
 =head2 new
 
-  my $obj = My::Class->new($attrs);
+  my $row = My::Class->new(\%attrs);
+
+  my $row = $schema->resultset('MySource')->new(\%colsandvalues);
+
+=over
+
+=item Arguments: \%attrs or \%colsandvalues
+
+=item Returns: A Row object
+
+=back
+
+While you can create a new row object by calling C<new> directly on
+this class, you are better off calling it on a
+L<DBIx::Class::ResultSet> object.
 
-Creates a new row object from column => value mappings passed as a hash ref
+When calling it directly, you will not get a complete, usable row
+object until you pass or set the C<source_handle> attribute, to a
+L<DBIx::Class::ResultSource> instance that is attached to a
+L<DBIx::Class::Schema> with a valid connection.
+
+C<$attrs> is a hashref of column name, value data. It can also contain
+some other attributes such as the C<source_handle>.
 
 Passing an object, or an arrayref of objects as a value will call
 L<DBIx::Class::Relationship::Base/set_from_related> for you. When
@@ -37,6 +77,23 @@ passed objects.
 
 For a more involved explanation, see L<DBIx::Class::ResultSet/create>.
 
+Please note that if a value is not passed to new, no value will be sent
+in the SQL INSERT call, and the column will therefore assume whatever
+default value was specified in your database. While DBIC will retrieve the
+value of autoincrement columns, it will never make an explicit database
+trip to retrieve default values assigned by the RDBMS. You can explicitly
+request that all values be fetched back from the database by calling
+L</discard_changes>, or you can supply an explicit C<undef> to columns
+with NULL as the default, and save yourself a SELECT.
+
+ CAVEAT:
+
+ The behavior described above will backfire if you use a foreign key column
+ with a database-defined default. If you call the relationship accessor on
+ an object that doesn't have a set value for the FK column, DBIC will throw
+ an exception, as it has no way of knowing the PK of the related object (if
+ there is one).
+
 =cut
 
 ## It needs to store the new objects somewhere, and call insert on that list later when insert is called on this object. We may need an accessor for these so the user can retrieve them, if just doing ->new().
@@ -46,67 +103,123 @@ For a more involved explanation, see L<DBIx::Class::ResultSet/create>.
 ## check Relationship::CascadeActions and Relationship::Accessor for compat
 ## tests!
 
+sub __new_related_find_or_new_helper {
+  my ($self, $relname, $data) = @_;
+  if ($self->__their_pk_needs_us($relname, $data)) {
+    MULTICREATE_DEBUG and warn "MC $self constructing $relname via new_result";
+    return $self->result_source
+                ->related_source($relname)
+                ->resultset
+                ->new_result($data);
+  }
+  if ($self->result_source->_pk_depends_on($relname, $data)) {
+    MULTICREATE_DEBUG and warn "MC $self constructing $relname via find_or_new";
+    return $self->result_source
+                ->related_source($relname)
+                ->resultset
+                ->find_or_new($data);
+  }
+  MULTICREATE_DEBUG and warn "MC $self constructing $relname via find_or_new_related";
+  return $self->find_or_new_related($relname, $data);
+}
+
+sub __their_pk_needs_us { # this should maybe be in resultsource.
+  my ($self, $relname, $data) = @_;
+  my $source = $self->result_source;
+  my $reverse = $source->reverse_relationship_info($relname);
+  my $rel_source = $source->related_source($relname);
+  my $us = { $self->get_columns };
+  foreach my $key (keys %$reverse) {
+    # if their primary key depends on us, then we have to
+    # just create a result and we'll fill it out afterwards
+    return 1 if $rel_source->_pk_depends_on($key, $us);
+  }
+  return 0;
+}
+
 sub new {
   my ($class, $attrs) = @_;
   $class = ref $class if ref $class;
 
-  my $new = { _column_data => {} };
+  my $new = {
+      _column_data          => {},
+  };
   bless $new, $class;
 
   if (my $handle = delete $attrs->{-source_handle}) {
     $new->_source_handle($handle);
   }
-  if (my $source = delete $attrs->{-result_source}) {
+
+  my $source;
+  if ($source = delete $attrs->{-result_source}) {
     $new->result_source($source);
   }
 
+  if (my $related = delete $attrs->{-cols_from_relations}) {
+    @{$new->{_ignore_at_insert}={}}{@$related} = ();
+  }
+
   if ($attrs) {
     $new->throw_exception("attrs must be a hashref")
       unless ref($attrs) eq 'HASH';
-    
+
     my ($related,$inflated);
-    ## Pretend all the rels are actual objects, unset below if not, for insert() to fix
-    $new->{_rel_in_storage} = 1;
 
     foreach my $key (keys %$attrs) {
       if (ref $attrs->{$key}) {
         ## Can we extract this lot to use with update(_or .. ) ?
-        my $info = $class->relationship_info($key);
-        if ($info && $info->{attrs}{accessor}
-          && $info->{attrs}{accessor} eq 'single')
-        {
+        $new->throw_exception("Can't do multi-create without result source")
+          unless $source;
+        my $info = $source->relationship_info($key);
+        my $acc_type = $info->{attrs}{accessor} || '';
+        if ($acc_type eq 'single') {
           my $rel_obj = delete $attrs->{$key};
           if(!Scalar::Util::blessed($rel_obj)) {
-            $rel_obj = $new->find_or_new_related($key, $rel_obj);
+            $rel_obj = $new->__new_related_find_or_new_helper($key, $rel_obj);
           }
 
-          $new->{_rel_in_storage} = 0 unless ($rel_obj->in_storage);
+          if ($rel_obj->in_storage) {
+            $new->{_rel_in_storage}{$key} = 1;
+            $new->set_from_related($key, $rel_obj);
+          } else {
+            MULTICREATE_DEBUG and warn "MC $new uninserted $key $rel_obj\n";
+          }
 
-          $new->set_from_related($key, $rel_obj);        
           $related->{$key} = $rel_obj;
           next;
-        } elsif ($info && $info->{attrs}{accessor}
-            && $info->{attrs}{accessor} eq 'multi'
-            && ref $attrs->{$key} eq 'ARRAY') {
+        }
+        elsif ($acc_type eq 'multi' && ref $attrs->{$key} eq 'ARRAY' ) {
           my $others = delete $attrs->{$key};
-          foreach my $rel_obj (@$others) {
+          my $total = @$others;
+          my @objects;
+          foreach my $idx (0 .. $#$others) {
+            my $rel_obj = $others->[$idx];
             if(!Scalar::Util::blessed($rel_obj)) {
-              $rel_obj = $new->new_related($key, $rel_obj);
-              $new->{_rel_in_storage} = 0;
+              $rel_obj = $new->__new_related_find_or_new_helper($key, $rel_obj);
             }
 
-            $new->{_rel_in_storage} = 0 unless ($rel_obj->in_storage);
+            if ($rel_obj->in_storage) {
+              $rel_obj->throw_exception ('A multi relationship can not be pre-existing when doing multicreate. Something went wrong');
+            } else {
+              MULTICREATE_DEBUG and
+                warn "MC $new uninserted $key $rel_obj (${\($idx+1)} of $total)\n";
+            }
+            push(@objects, $rel_obj);
           }
-          $related->{$key} = $others;
+          $related->{$key} = \@objects;
           next;
-        } elsif ($info && $info->{attrs}{accessor}
-          && $info->{attrs}{accessor} eq 'filter')
-        {
+        }
+        elsif ($acc_type eq 'filter') {
           ## 'filter' should disappear and get merged in with 'single' above!
           my $rel_obj = delete $attrs->{$key};
           if(!Scalar::Util::blessed($rel_obj)) {
-            $rel_obj = $new->find_or_new_related($key, $rel_obj);
-            $new->{_rel_in_storage} = 0 unless ($rel_obj->in_storage);
+            $rel_obj = $new->__new_related_find_or_new_helper($key, $rel_obj);
+          }
+          if ($rel_obj->in_storage) {
+            $new->{_rel_in_storage}{$key} = 1;
+          }
+          else {
+            MULTICREATE_DEBUG and warn "MC $new uninserted $key $rel_obj";
           }
           $inflated->{$key} = $rel_obj;
           next;
@@ -118,7 +231,7 @@ sub new {
       }
       $new->throw_exception("No such column $key on $class")
         unless $class->has_column($key);
-      $new->store_column($key => $attrs->{$key});          
+      $new->store_column($key => $attrs->{$key});
     }
 
     $new->{_relationship_data} = $related if $related;
@@ -130,13 +243,24 @@ sub new {
 
 =head2 insert
 
-  $obj->insert;
+  $row->insert;
+
+=over
+
+=item Arguments: none
+
+=item Returns: The Row object
 
-Inserts an object into the database if it isn't already in
-there. Returns the object itself. Requires the object's result source to
-be set, or the class to have a result_source_instance method. To insert
-an entirely new object into the database, use C<create> (see
-L<DBIx::Class::ResultSet/create>).
+=back
+
+Inserts an object previously created by L</new> into the database if
+it isn't already in there. Returns the object itself. Requires the
+object's result source to be set, or the class to have a
+result_source_instance method. To insert an entirely new row into
+the database, use C<create> (see L<DBIx::Class::ResultSet/create>).
+
+To fetch an uninserted row object, call
+L<new|DBIx::Class::ResultSet/new> on a resultset.
 
 This will also insert any uninserted, related objects held inside this
 one, see L<DBIx::Class::ResultSet/create> for more details.
@@ -155,67 +279,65 @@ sub insert {
   my $rollback_guard;
 
   # Check if we stored uninserted relobjs here in new()
-  my %related_stuff = (%{$self->{_relationship_data} || {}}, 
+  my %related_stuff = (%{$self->{_relationship_data} || {}},
                        %{$self->{_inflated_column} || {}});
 
-  if(!$self->{_rel_in_storage}) {
-
-    # The guard will save us if we blow out of this scope via die
-    $rollback_guard = $source->storage->txn_scope_guard;
-
-    ## Should all be in relationship_data, but we need to get rid of the
-    ## 'filter' reltype..
-    ## These are the FK rels, need their IDs for the insert.
-
-    my @pri = $self->primary_columns;
+  # insert what needs to be inserted before us
+  my %pre_insert;
+  for my $relname (keys %related_stuff) {
+    my $rel_obj = $related_stuff{$relname};
 
-    REL: foreach my $relname (keys %related_stuff) {
+    if (! $self->{_rel_in_storage}{$relname}) {
+      next unless (Scalar::Util::blessed($rel_obj)
+                    && $rel_obj->isa('DBIx::Class::Row'));
 
-      my $rel_obj = $related_stuff{$relname};
+      next unless $source->_pk_depends_on(
+                    $relname, { $rel_obj->get_columns }
+                  );
 
-      next REL unless (Scalar::Util::blessed($rel_obj)
-                       && $rel_obj->isa('DBIx::Class::Row'));
+      # The guard will save us if we blow out of this scope via die
+      $rollback_guard ||= $source->storage->txn_scope_guard;
 
-      my $cond = $source->relationship_info($relname)->{cond};
+      MULTICREATE_DEBUG and warn "MC $self pre-reconstructing $relname $rel_obj\n";
 
-      next REL unless ref($cond) eq 'HASH';
+      my $them = { %{$rel_obj->{_relationship_data} || {} }, $rel_obj->get_inflated_columns };
+      my $re = $self->result_source
+                    ->related_source($relname)
+                    ->resultset
+                    ->find_or_create($them);
 
-      # map { foreign.foo => 'self.bar' } to { bar => 'foo' }
-
-      my $keyhash = { map { my $x = $_; $x =~ s/.*\.//; $x; } reverse %$cond };
-
-      # assume anything that references our PK probably is dependent on us
-      # rather than vice versa, unless the far side is (a) defined or (b)
-      # auto-increment
+      %{$rel_obj} = %{$re};
+      $self->{_rel_in_storage}{$relname} = 1;
+    }
 
-      foreach my $p (@pri) {
-        if (exists $keyhash->{$p}) {
-          unless (defined($rel_obj->get_column($keyhash->{$p}))
-                  || $rel_obj->column_info($keyhash->{$p})
-                             ->{is_auto_increment}) {
-            next REL;
-          }
-        }
-      }
+    $self->set_from_related($relname, $rel_obj);
+    delete $related_stuff{$relname};
+  }
 
-      $rel_obj->insert();
-      $self->set_from_related($relname, $rel_obj);
-      delete $related_stuff{$relname};
-    }
+  # start a transaction here if not started yet and there is more stuff
+  # to insert after us
+  if (keys %related_stuff) {
+    $rollback_guard ||= $source->storage->txn_scope_guard
   }
 
-  $source->storage->insert($source, { $self->get_columns });
+  MULTICREATE_DEBUG and do {
+    no warnings 'uninitialized';
+    warn "MC $self inserting (".join(', ', $self->get_columns).")\n";
+  };
+  my $updated_cols = $source->storage->insert($source, { $self->get_columns });
+  foreach my $col (keys %$updated_cols) {
+    $self->store_column($col, $updated_cols->{$col});
+  }
 
   ## PK::Auto
   my @auto_pri = grep {
-                   !defined $self->get_column($_) || 
-                   ref($self->get_column($_)) eq 'SCALAR'
+                  (not defined $self->get_column($_))
+                    ||
+                  (ref($self->get_column($_)) eq 'SCALAR')
                  } $self->primary_columns;
 
   if (@auto_pri) {
-    #$self->throw_exception( "More than one possible key found for auto-inc on ".ref $self )
-    #  if defined $too_many;
-
+    MULTICREATE_DEBUG and warn "MC $self fetching missing PKs ".join(', ', @auto_pri)."\n";
     my $storage = $self->result_source->storage;
     $self->throw_exception( "Missing primary key but Storage doesn't support last_insert_id" )
       unless $storage->can('last_insert_id');
@@ -225,63 +347,130 @@ sub insert {
     $self->store_column($auto_pri[$_] => $ids[$_]) for 0 .. $#ids;
   }
 
-  if(!$self->{_rel_in_storage}) {
-    ## Now do the has_many rels, that need $selfs ID.
-    foreach my $relname (keys %related_stuff) {
-      my $rel_obj = $related_stuff{$relname};
-      my @cands;
-      if (Scalar::Util::blessed($rel_obj)
-          && $rel_obj->isa('DBIx::Class::Row')) {
-        @cands = ($rel_obj);
-      } elsif (ref $rel_obj eq 'ARRAY') {
-        @cands = @$rel_obj;
-      }
-      if (@cands) {
-        my $reverse = $source->reverse_relationship_info($relname);
-        foreach my $obj (@cands) {
-          $obj->set_from_related($_, $self) for keys %$reverse;
-          $obj->insert() unless ($obj->in_storage || $obj->result_source->resultset->search({$obj->get_columns})->count);
+
+  $self->{_dirty_columns} = {};
+  $self->{related_resultsets} = {};
+
+  foreach my $relname (keys %related_stuff) {
+    next unless $source->has_relationship ($relname);
+
+    my @cands = ref $related_stuff{$relname} eq 'ARRAY'
+      ? @{$related_stuff{$relname}}
+      : $related_stuff{$relname}
+    ;
+
+    if (@cands
+          && Scalar::Util::blessed($cands[0])
+            && $cands[0]->isa('DBIx::Class::Row')
+    ) {
+      my $reverse = $source->reverse_relationship_info($relname);
+      foreach my $obj (@cands) {
+        $obj->set_from_related($_, $self) for keys %$reverse;
+        my $them = { %{$obj->{_relationship_data} || {} }, $obj->get_inflated_columns };
+        if ($self->__their_pk_needs_us($relname, $them)) {
+          if (exists $self->{_ignore_at_insert}{$relname}) {
+            MULTICREATE_DEBUG and warn "MC $self skipping post-insert on $relname";
+          } else {
+            MULTICREATE_DEBUG and warn "MC $self re-creating $relname $obj";
+            my $re = $self->result_source
+                          ->related_source($relname)
+                          ->resultset
+                          ->create($them);
+            %{$obj} = %{$re};
+            MULTICREATE_DEBUG and warn "MC $self new $relname $obj";
+          }
+        } else {
+          MULTICREATE_DEBUG and warn "MC $self post-inserting $obj";
+          $obj->insert();
         }
       }
     }
-    $rollback_guard->commit;
   }
 
   $self->in_storage(1);
-  $self->{_dirty_columns} = {};
-  $self->{related_resultsets} = {};
-  undef $self->{_orig_ident};
+  delete $self->{_orig_ident};
+  delete $self->{_ignore_at_insert};
+  $rollback_guard->commit if $rollback_guard;
+
   return $self;
 }
 
 =head2 in_storage
 
-  $obj->in_storage; # Get value
-  $obj->in_storage(1); # Set value
+  $row->in_storage; # Get value
+  $row->in_storage(1); # Set value
+
+=over
+
+=item Arguments: none or 1|0
 
-Indicates whether the object exists as a row in the database or not
+=item Returns: 1|0
+
+=back
+
+Indicates whether the object exists as a row in the database or
+not. This is set to true when L<DBIx::Class::ResultSet/find>,
+L<DBIx::Class::ResultSet/create> or L<DBIx::Class::ResultSet/insert>
+are used.
+
+Creating a row object using L<DBIx::Class::ResultSet/new>, or calling
+L</delete> on one, sets it to false.
 
 =cut
 
 sub in_storage {
   my ($self, $val) = @_;
   $self->{_in_storage} = $val if @_ > 1;
-  return $self->{_in_storage};
+  return $self->{_in_storage} ? 1 : 0;
 }
 
 =head2 update
 
-  $obj->update \%columns?;
+  $row->update(\%columns?)
+
+=over
+
+=item Arguments: none or a hashref
+
+=item Returns: The Row object
+
+=back
+
+Throws an exception if the row object is not yet in the database,
+according to L</in_storage>.
+
+This method issues an SQL UPDATE query to commit any changes to the
+object to the database if required.
 
-Must be run on an object that is already in the database; issues an SQL
-UPDATE query to commit any changes to the object to the database if
-required.
+Also takes an optional hashref of C<< column_name => value> >> pairs
+to update on the object first. Be aware that the hashref will be
+passed to C<set_inflated_columns>, which might edit it in place, so
+don't rely on it being the same after a call to C<update>.  If you
+need to preserve the hashref, it is sufficient to pass a shallow copy
+to C<update>, e.g. ( { %{ $href } } )
 
-Also takes an options hashref of C<< column_name => value> pairs >> to update
-first. But be aware that the hashref will be passed to
-C<set_inflated_columns>, which might edit it in place, so dont rely on it being
-the same after a call to C<update>.  If you need to preserve the hashref, it is
-sufficient to pass a shallow copy to C<update>, e.g. ( { %{ $href } } )
+If the values passed or any of the column values set on the object
+contain scalar references, e.g.:
+
+  $row->last_modified(\'NOW()');
+  # OR
+  $row->update({ last_modified => \'NOW()' });
+
+The update will pass the values verbatim into SQL. (See
+L<SQL::Abstract> docs).  The values in your Row object will NOT change
+as a result of the update call, if you want the object to be updated
+with the actual values from the database, call L</discard_changes>
+after the update.
+
+  $row->update()->discard_changes();
+
+To determine before calling this method, which column values have
+changed and will be updated, call L</get_dirty_columns>.
+
+To check if any columns will be updated, call L</is_changed>.
+
+To force a column to be updated, call L</make_column_dirty> before
+this method.
 
 =cut
 
@@ -312,16 +501,42 @@ sub update {
 
 =head2 delete
 
-  $obj->delete
+  $row->delete
+
+=over
+
+=item Arguments: none
+
+=item Returns: The Row object
+
+=back
 
-Deletes the object from the database. The object is still perfectly
-usable, but C<< ->in_storage() >> will now return 0 and the object must
-reinserted using C<< ->insert() >> before C<< ->update() >> can be used
-on it. If you delete an object in a class with a C<has_many>
-relationship, all the related objects will be deleted as well. To turn
-this behavior off, pass C<< cascade_delete => 0 >> in the C<$attr>
-hashref. Any database-level cascade or restrict will take precedence
-over a DBIx-Class-based cascading delete. See also L<DBIx::Class::ResultSet/delete>.
+Throws an exception if the object is not in the database according to
+L</in_storage>. Runs an SQL DELETE statement using the primary key
+values to locate the row.
+
+The object is still perfectly usable, but L</in_storage> will
+now return 0 and the object must be reinserted using L</insert>
+before it can be used to L</update> the row again.
+
+If you delete an object in a class with a C<has_many> relationship, an
+attempt is made to delete all the related objects as well. To turn
+this behaviour off, pass C<< cascade_delete => 0 >> in the C<$attr>
+hashref of the relationship, see L<DBIx::Class::Relationship>. Any
+database-level cascade or restrict will take precedence over a
+DBIx-Class-based cascading delete, since DBIx-Class B<deletes the
+main row first> and only then attempts to delete any remaining related
+rows.
+
+If you delete an object within a txn_do() (see L<DBIx::Class::Storage/txn_do>)
+and the transaction subsequently fails, the row object will remain marked as
+not being in storage. If you know for a fact that the object is still in
+storage (i.e. by inspecting the cause of the transaction's failure), you can
+use C<< $obj->in_storage(1) >> to restore consistency between the object and
+the database. This would allow a subsequent C<< $obj->delete >> to work
+as expected.
+
+See also L<DBIx::Class::ResultSet/delete>.
 
 =cut
 
@@ -329,7 +544,7 @@ sub delete {
   my $self = shift;
   if (ref $self) {
     $self->throw_exception( "Not in database" ) unless $self->in_storage;
-    my $ident_cond = $self->ident_condition;
+    my $ident_cond = $self->{_orig_ident} || $self->ident_condition;
     $self->throw_exception("Cannot safely delete a row in a PK-less table")
       if ! keys %$ident_cond;
     foreach my $column (keys %$ident_cond) {
@@ -351,12 +566,31 @@ sub delete {
 
 =head2 get_column
 
-  my $val = $obj->get_column($col);
+  my $val = $row->get_column($col);
+
+=over
+
+=item Arguments: $columnname
+
+=item Returns: The value of the column
+
+=back
+
+Throws an exception if the column name given doesn't exist according
+to L</has_column>.
 
-Gets a column value from a row object. Does not do any queries; the column 
-must have already been fetched from the database and stored in the object. If 
-there is an inflated value stored that has not yet been deflated, it is deflated
-when the method is invoked.
+Returns a raw column value from the row object, if it has already
+been fetched from the database or set by an accessor.
+
+If an L<inflated value|DBIx::Class::InflateColumn> has been set, it
+will be deflated and returned.
+
+Note that if you used the C<columns> or the C<select/as>
+L<search attributes|DBIx::Class::ResultSet/ATTRIBUTES> on the resultset from
+which C<$row> was derived, and B<did not include> C<$columnname> in the list,
+this method will return C<undef> even if the database contains some value.
+
+To retrieve all loaded column values as a hash, use L</get_columns>.
 
 =cut
 
@@ -366,7 +600,7 @@ sub get_column {
   return $self->{_column_data}{$column} if exists $self->{_column_data}{$column};
   if (exists $self->{_inflated_column}{$column}) {
     return $self->store_column($column,
-      $self->_deflated_column($column, $self->{_inflated_column}{$column}));   
+      $self->_deflated_column($column, $self->{_inflated_column}{$column}));
   }
   $self->throw_exception( "No such column '${column}'" ) unless $self->has_column($column);
   return undef;
@@ -374,10 +608,18 @@ sub get_column {
 
 =head2 has_column_loaded
 
-  if ( $obj->has_column_loaded($col) ) {
+  if ( $row->has_column_loaded($col) ) {
      print "$col has been loaded from db";
   }
 
+=over
+
+=item Arguments: $columnname
+
+=item Returns: 0|1
+
+=back
+
 Returns a true value if the column value has been loaded from the
 database (or set locally).
 
@@ -392,9 +634,20 @@ sub has_column_loaded {
 
 =head2 get_columns
 
-  my %data = $obj->get_columns;
+  my %data = $row->get_columns;
+
+=over
+
+=item Arguments: none
 
-Does C<get_column>, for all column values at once.
+=item Returns: A hash of columnname, value pairs.
+
+=back
+
+Returns all loaded column data as a hash, containing raw values. To
+get just one value for a particular column, use L</get_column>.
+
+See L</get_inflated_columns> to get the inflated values.
 
 =cut
 
@@ -411,9 +664,20 @@ sub get_columns {
 
 =head2 get_dirty_columns
 
-  my %data = $obj->get_dirty_columns;
+  my %data = $row->get_dirty_columns;
+
+=over
+
+=item Arguments: none
 
-Identical to get_columns but only returns those that have been changed.
+=item Returns: A hash of column, value pairs
+
+=back
+
+Only returns the column, value pairs for those columns that have been
+changed on this object since the last L</update> or L</insert> call.
+
+See L</get_columns> to fetch all column/value pairs.
 
 =cut
 
@@ -423,47 +687,182 @@ sub get_dirty_columns {
            keys %{$self->{_dirty_columns}};
 }
 
+=head2 make_column_dirty
+
+  $row->make_column_dirty($col)
+
+=over
+
+=item Arguments: $columnname
+
+=item Returns: undefined
+
+=back
+
+Throws an exception if the column does not exist.
+
+Marks a column as having been changed regardless of whether it has
+really changed.
+
+=cut
+sub make_column_dirty {
+  my ($self, $column) = @_;
+
+  $self->throw_exception( "No such column '${column}'" )
+    unless exists $self->{_column_data}{$column} || $self->has_column($column);
+
+  # the entire clean/dirty code relies on exists, not on true/false
+  return 1 if exists $self->{_dirty_columns}{$column};
+
+  $self->{_dirty_columns}{$column} = 1;
+
+  # if we are just now making the column dirty, and if there is an inflated
+  # value, force it over the deflated one
+  if (exists $self->{_inflated_column}{$column}) {
+    $self->store_column($column,
+      $self->_deflated_column(
+        $column, $self->{_inflated_column}{$column}
+      )
+    );
+  }
+}
+
 =head2 get_inflated_columns
 
-  my $inflated_data = $obj->get_inflated_columns;
+  my %inflated_data = $obj->get_inflated_columns;
+
+=over
+
+=item Arguments: none
+
+=item Returns: A hash of column, object|value pairs
 
-Similar to get_columns but objects are returned for inflated columns instead of their raw non-inflated values.
+=back
+
+Returns a hash of all column keys and associated values. Values for any
+columns set to use inflation will be inflated and returns as objects.
+
+See L</get_columns> to get the uninflated values.
+
+See L<DBIx::Class::InflateColumn> for how to setup inflation.
 
 =cut
 
 sub get_inflated_columns {
   my $self = shift;
-  return map {
-    my $accessor = $self->column_info($_)->{'accessor'} || $_;
-    ($_ => $self->$accessor);
-  } $self->columns;
+
+  my %loaded_colinfo = (map
+    { $_ => $self->column_info($_) }
+    (grep { $self->has_column_loaded($_) } $self->columns)
+  );
+
+  my %inflated;
+  for my $col (keys %loaded_colinfo) {
+    if (exists $loaded_colinfo{$col}{accessor}) {
+      my $acc = $loaded_colinfo{$col}{accessor};
+      $inflated{$col} = $self->$acc if defined $acc;
+    }
+    else {
+      $inflated{$col} = $self->$col;
+    }
+  }
+
+  # return all loaded columns with the inflations overlayed on top
+  return ($self->get_columns, %inflated);
+}
+
+sub _is_column_numeric {
+   my ($self, $column) = @_;
+    my $colinfo = $self->column_info ($column);
+
+    # cache for speed (the object may *not* have a resultsource instance)
+    if (not defined $colinfo->{is_numeric} && $self->_source_handle) {
+      $colinfo->{is_numeric} =
+        $self->result_source->schema->storage->is_datatype_numeric ($colinfo->{data_type})
+          ? 1
+          : 0
+        ;
+    }
+
+    return $colinfo->{is_numeric};
 }
 
 =head2 set_column
 
-  $obj->set_column($col => $val);
+  $row->set_column($col => $val);
 
-Sets a column value. If the new value is different from the old one,
-the column is marked as dirty for when you next call $obj->update.
+=over
+
+=item Arguments: $columnname, $value
+
+=item Returns: $value
+
+=back
+
+Sets a raw column value. If the new value is different from the old one,
+the column is marked as dirty for when you next call L</update>.
+
+If passed an object or reference as a value, this method will happily
+attempt to store it, and a later L</insert> or L</update> will try and
+stringify/numify as appropriate. To set an object to be deflated
+instead, see L</set_inflated_columns>.
 
 =cut
 
 sub set_column {
-  my $self = shift;
-  my ($column) = @_;
+  my ($self, $column, $new_value) = @_;
+
   $self->{_orig_ident} ||= $self->ident_condition;
-  my $old = $self->get_column($column);
-  my $ret = $self->store_column(@_);
-  $self->{_dirty_columns}{$column} = 1
-    if (defined $old ^ defined $ret) || (defined $old && $old ne $ret);
-  return $ret;
+  my $old_value = $self->get_column($column);
+
+  $new_value = $self->store_column($column, $new_value);
+
+  my $dirty;
+  if (!$self->in_storage) { # no point tracking dirtyness on uninserted data
+    $dirty = 1;
+  }
+  elsif (defined $old_value xor defined $new_value) {
+    $dirty = 1;
+  }
+  elsif (not defined $old_value) {  # both undef
+    $dirty = 0;
+  }
+  elsif ($old_value eq $new_value) {
+    $dirty = 0;
+  }
+  else {  # do a numeric comparison if datatype allows it
+    if ($self->_is_column_numeric($column)) {
+      $dirty = $old_value != $new_value;
+    }
+    else {
+      $dirty = 1;
+    }
+  }
+
+  # sadly the update code just checks for keys, not for their value
+  $self->{_dirty_columns}{$column} = 1 if $dirty;
+
+  # XXX clear out the relation cache for this column
+  delete $self->{related_resultsets}{$column};
+
+  return $new_value;
 }
 
 =head2 set_columns
 
-  my $copy = $orig->set_columns({ $col => $val, ... });
+  $row->set_columns({ $col => $val, ... });
 
-Sets more than one column value at once.
+=over
+
+=item Arguments: \%columndata
+
+=item Returns: The Row object
+
+=back
+
+Sets multiple column, raw value pairs at once.
+
+Works as L</set_column>.
 
 =cut
 
@@ -477,13 +876,34 @@ sub set_columns {
 
 =head2 set_inflated_columns
 
-  my $copy = $orig->set_inflated_columns({ $col => $val, $rel => $obj, ... });
+  $row->set_inflated_columns({ $col => $val, $relname => $obj, ... });
+
+=over
+
+=item Arguments: \%columndata
+
+=item Returns: The Row object
+
+=back
 
-Sets more than one column value at once, taking care to respect inflations and
-relationships if relevant. Be aware that this hashref might be edited in place,
-so dont rely on it being the same after a call to C<set_inflated_columns>. If
-you need to preserve the hashref, it is sufficient to pass a shallow copy to
-C<set_inflated_columns>, e.g. ( { %{ $href } } )
+Sets more than one column value at once. Any inflated values are
+deflated and the raw values stored.
+
+Any related values passed as Row objects, using the relation name as a
+key, are reduced to the appropriate foreign key values and stored. If
+instead of related row objects, a hashref of column, value data is
+passed, will create the related object first then store.
+
+Will even accept arrayrefs of data as a value to a
+L<DBIx::Class::Relationship/has_many> key, and create the related
+objects if necessary.
+
+Be aware that the input hashref might be edited in place, so don't rely
+on it being the same after a call to C<set_inflated_columns>. If you
+need to preserve the hashref, it is sufficient to pass a shallow copy
+to C<set_inflated_columns>, e.g. ( { %{ $href } } )
+
+See also L<DBIx::Class::Relationship::Base/set_from_related>.
 
 =cut
 
@@ -492,40 +912,49 @@ sub set_inflated_columns {
   foreach my $key (keys %$upd) {
     if (ref $upd->{$key}) {
       my $info = $self->relationship_info($key);
-      if ($info && $info->{attrs}{accessor}
-        && $info->{attrs}{accessor} eq 'single')
-      {
+      my $acc_type = $info->{attrs}{accessor} || '';
+      if ($acc_type eq 'single') {
         my $rel = delete $upd->{$key};
         $self->set_from_related($key => $rel);
-        $self->{_relationship_data}{$key} = $rel;          
-      } elsif ($info && $info->{attrs}{accessor}
-        && $info->{attrs}{accessor} eq 'multi'
-        && ref $upd->{$key} eq 'ARRAY') {
-        my $others = delete $upd->{$key};
-        foreach my $rel_obj (@$others) {
-          if(!Scalar::Util::blessed($rel_obj)) {
-            $rel_obj = $self->create_related($key, $rel_obj);
-          }
-        }
-        $self->{_relationship_data}{$key} = $others; 
-#            $related->{$key} = $others;
-        next;
+        $self->{_relationship_data}{$key} = $rel;
       }
-      elsif ($self->has_column($key)
-        && exists $self->column_info($key)->{_inflate_info})
-      {
-        $self->set_inflated_column($key, delete $upd->{$key});          
+      elsif ($acc_type eq 'multi') {
+        $self->throw_exception(
+          "Recursive update is not supported over relationships of type '$acc_type' ($key)"
+        );
+      }
+      elsif ($self->has_column($key) && exists $self->column_info($key)->{_inflate_info}) {
+        $self->set_inflated_column($key, delete $upd->{$key});
       }
     }
   }
-  $self->set_columns($upd);    
+  $self->set_columns($upd);
 }
 
 =head2 copy
 
   my $copy = $orig->copy({ change => $to, ... });
 
-Inserts a new row with the specified changes.
+=over
+
+=item Arguments: \%replacementdata
+
+=item Returns: The Row object copy
+
+=back
+
+Inserts a new row into the database, as a copy of the original
+object. If a hashref of replacement data is supplied, these will take
+precedence over data in the original. Also any columns which have
+the L<column info attribute|DBIx::Class::ResultSource/add_columns>
+C<< is_auto_increment => 1 >> are explicitly removed before the copy,
+so that the database can insert its own autoincremented values into
+the new object.
+
+Relationships will be followed by the copy procedure B<only> if the
+relationship specifies a true value for its
+L<cascade_copy|DBIx::Class::Relationship::Base> attribute. C<cascade_copy>
+is set by default on C<has_many> relationships and unset on all others.
 
 =cut
 
@@ -545,8 +974,8 @@ sub copy {
   $new->set_inflated_columns($changes);
   $new->insert;
 
-  # Its possible we'll have 2 relations to the same Source. We need to make 
-  # sure we don't try to insert the same row twice esle we'll violate unique
+  # Its possible we'll have 2 relations to the same Source. We need to make
+  # sure we don't try to insert the same row twice else we'll violate unique
   # constraints
   my $rels_copied = {};
 
@@ -554,8 +983,8 @@ sub copy {
     my $rel_info = $self->result_source->relationship_info($rel);
 
     next unless $rel_info->{attrs}{cascade_copy};
-  
-    my $resolved = $self->result_source->resolve_condition(
+
+    my $resolved = $self->result_source->_resolve_condition(
       $rel_info->{cond}, $rel, $new
     );
 
@@ -566,16 +995,29 @@ sub copy {
       $copied->{$id_str} = 1;
       my $rel_copy = $related->copy($resolved);
     }
- 
+
   }
   return $new;
 }
 
 =head2 store_column
 
-  $obj->store_column($col => $val);
+  $row->store_column($col => $val);
+
+=over
+
+=item Arguments: $columnname, $value
+
+=item Returns: The value sent to storage
+
+=back
 
-Sets a column value without marking it as dirty.
+Set a raw value for a column without marking it as changed. This
+method is used internally by L</set_column> which you should probably
+be using.
+
+This is the lowest level at which data is set on a row object,
+extend this method to catch all data setting methods.
 
 =cut
 
@@ -592,7 +1034,25 @@ sub store_column {
 
   Class->inflate_result($result_source, \%me, \%prefetch?)
 
-Called by ResultSet to inflate a result from storage
+=over
+
+=item Arguments: $result_source, \%columndata, \%prefetcheddata
+
+=item Returns: A Row object
+
+=back
+
+All L<DBIx::Class::ResultSet> methods that retrieve data from the
+database and turn it into row objects call this method.
+
+Extend this method in your Result classes to hook into this process,
+for example to rebless the result into a different class.
+
+Reblessing can also be done more easily by setting C<result_class> in
+your Result class. See L<DBIx::Class::ResultSource/result_class>.
+
+Different types of results can also be created from a particular
+L<DBIx::Class::ResultSet>, see L<DBIx::Class::ResultSet/result_class>.
 
 =cut
 
@@ -602,64 +1062,85 @@ sub inflate_result {
   my ($source_handle) = $source;
 
   if ($source->isa('DBIx::Class::ResultSourceHandle')) {
-      $source = $source_handle->resolve
-  } else {
-      $source_handle = $source->handle
+    $source = $source_handle->resolve
+  } 
+  else {
+    $source_handle = $source->handle
   }
 
   my $new = {
     _source_handle => $source_handle,
     _column_data => $me,
-    _in_storage => 1
   };
   bless $new, (ref $class || $class);
 
-  my $schema;
   foreach my $pre (keys %{$prefetch||{}}) {
-    my $pre_val = $prefetch->{$pre};
-    my $pre_source = $source->related_source($pre);
-    $class->throw_exception("Can't prefetch non-existent relationship ${pre}")
-      unless $pre_source;
-    if (ref($pre_val->[0]) eq 'ARRAY') { # multi
-      my @pre_objects;
-      foreach my $pre_rec (@$pre_val) {
-        unless ($pre_source->primary_columns == grep { exists $pre_rec->[0]{$_}
-           and defined $pre_rec->[0]{$_} } $pre_source->primary_columns) {
-          next;
+
+    my $pre_source = $source->related_source($pre)
+      or $class->throw_exception("Can't prefetch non-existent relationship ${pre}");
+
+    my $accessor = $source->relationship_info($pre)->{attrs}{accessor}
+      or $class->throw_exception("No accessor for prefetched $pre");
+
+    my @pre_vals;
+    if (ref $prefetch->{$pre}[0] eq 'ARRAY') {
+      @pre_vals = @{$prefetch->{$pre}};
+    }
+    elsif ($accessor eq 'multi') {
+      $class->throw_exception("Implicit prefetch (via select/columns) not supported with accessor 'multi'");
+    }
+    else {
+      @pre_vals = $prefetch->{$pre};
+    }
+
+    my @pre_objects;
+    for my $me_pref (@pre_vals) {
+
+        # FIXME - this should not be necessary
+        # the collapser currently *could* return bogus elements with all
+        # columns set to undef
+        my $has_def;
+        for (values %{$me_pref->[0]}) {
+          if (defined $_) {
+            $has_def++;
+            last;
+          }
         }
-        push(@pre_objects, $pre_source->result_class->inflate_result(
-                             $pre_source, @{$pre_rec}));
-      }
-      $new->related_resultset($pre)->set_cache(\@pre_objects);
-    } elsif (defined $pre_val->[0]) {
-      my $fetched;
-      unless ($pre_source->primary_columns == grep { exists $pre_val->[0]{$_}
-         and !defined $pre_val->[0]{$_} } $pre_source->primary_columns)
-      {
-        $fetched = $pre_source->result_class->inflate_result(
-                      $pre_source, @{$pre_val});
-      }
-      $new->related_resultset($pre)->set_cache([ $fetched ]);
-      my $accessor = $source->relationship_info($pre)->{attrs}{accessor};
-      $class->throw_exception("No accessor for prefetched $pre")
-       unless defined $accessor;
-      if ($accessor eq 'single') {
-        $new->{_relationship_data}{$pre} = $fetched;
-      } elsif ($accessor eq 'filter') {
-        $new->{_inflated_column}{$pre} = $fetched;
-      } else {
-       $class->throw_exception("Prefetch not supported with accessor '$accessor'");
-      }
+        next unless $has_def;
+
+        push @pre_objects, $pre_source->result_class->inflate_result(
+          $pre_source, @$me_pref
+        );
     }
+
+    if ($accessor eq 'single') {
+      $new->{_relationship_data}{$pre} = $pre_objects[0];
+    }
+    elsif ($accessor eq 'filter') {
+      $new->{_inflated_column}{$pre} = $pre_objects[0];
+    }
+
+    $new->related_resultset($pre)->set_cache(\@pre_objects);
   }
+
+  $new->in_storage (1);
   return $new;
 }
 
 =head2 update_or_insert
 
-  $obj->update_or_insert
+  $row->update_or_insert
 
-Updates the object if it's already in the db, else inserts it.
+=over
+
+=item Arguments: none
+
+=item Returns: Result of update or insert operation
+
+=back
+
+L</Update>s the object if it's already in the database, according to
+L</in_storage>, else L</insert>s it.
 
 =head2 insert_or_update
 
@@ -669,7 +1150,8 @@ Alias for L</update_or_insert>
 
 =cut
 
-*insert_or_update = \&update_or_insert;
+sub insert_or_update { shift->update_or_insert(@_) }
+
 sub update_or_insert {
   my $self = shift;
   return ($self->in_storage ? $self->update : $self->insert);
@@ -677,10 +1159,18 @@ sub update_or_insert {
 
 =head2 is_changed
 
-  my @changed_col_names = $obj->is_changed();
-  if ($obj->is_changed()) { ... }
+  my @changed_col_names = $row->is_changed();
+  if ($row->is_changed()) { ... }
 
-In array context returns a list of columns with uncommited changes, or
+=over
+
+=item Arguments: none
+
+=item Returns: 0|1 or @columnnames
+
+=back
+
+In list context returns a list of columns with uncommited changes, or
 in scalar context returns a true value if there are uncommitted
 changes.
 
@@ -692,7 +1182,15 @@ sub is_changed {
 
 =head2 is_column_changed
 
-  if ($obj->is_column_changed('col')) { ... }
+  if ($row->is_column_changed('col')) { ... }
+
+=over
+
+=item Arguments: $columname
+
+=item Returns: 0|1
+
+=back
 
 Returns a true value if the column has uncommitted changes.
 
@@ -705,9 +1203,17 @@ sub is_column_changed {
 
 =head2 result_source
 
-  my $resultsource = $object->result_source;
+  my $resultsource = $row->result_source;
+
+=over
+
+=item Arguments: none
 
-Accessor to the ResultSource this object was created from
+=item Returns: a ResultSource instance
+
+=back
+
+Accessor to the L<DBIx::Class::ResultSource> this object was created from.
 
 =cut
 
@@ -726,6 +1232,14 @@ sub result_source {
   $column_info = { .... };
   $class->register_column($column_name, $column_info);
 
+=over
+
+=item Arguments: $columnname, \%columninfo
+
+=item Returns: undefined
+
+=back
+
 Registers a column on the class. If the column_info has an 'accessor'
 key, creates an accessor named after the value if defined; if there is
 no such key, creates an accessor with the same name as the column
@@ -745,36 +1259,144 @@ sub register_column {
   $class->mk_group_accessors('column' => $acc);
 }
 
+=head2 get_from_storage
+
+  my $copy = $row->get_from_storage($attrs)
+
+=over
+
+=item Arguments: \%attrs
+
+=item Returns: A Row object
+
+=back
+
+Fetches a fresh copy of the Row object from the database and returns it.
+
+If passed the \%attrs argument, will first apply these attributes to
+the resultset used to find the row.
+
+This copy can then be used to compare to an existing row object, to
+determine if any changes have been made in the database since it was
+created.
+
+To just update your Row object with any latest changes from the
+database, use L</discard_changes> instead.
+
+The \%attrs argument should be compatible with
+L<DBIx::Class::ResultSet/ATTRIBUTES>.
+
+=cut
+
+sub get_from_storage {
+    my $self = shift @_;
+    my $attrs = shift @_;
+    my $resultset = $self->result_source->resultset;
+
+    if(defined $attrs) {
+      $resultset = $resultset->search(undef, $attrs);
+    }
+
+    return $resultset->find($self->{_orig_ident} || $self->ident_condition);
+}
+
+=head2 discard_changes ($attrs)
+
+Re-selects the row from the database, losing any changes that had
+been made.
+
+This method can also be used to refresh from storage, retrieving any
+changes made since the row was last read from storage.
+
+$attrs is expected to be a hashref of attributes suitable for passing as the
+second argument to $resultset->search($cond, $attrs);
+
+=cut
+
+sub discard_changes {
+  my ($self, $attrs) = @_;
+  delete $self->{_dirty_columns};
+  return unless $self->in_storage; # Don't reload if we aren't real!
+
+  # add a replication default to read from the master only
+  $attrs = { force_pool => 'master', %{$attrs||{}} };
+
+  if( my $current_storage = $self->get_from_storage($attrs)) {
+
+    # Set $self to the current.
+    %$self = %$current_storage;
+
+    # Avoid a possible infinite loop with
+    # sub DESTROY { $_[0]->discard_changes }
+    bless $current_storage, 'Do::Not::Exist';
+
+    return $self;
+  }
+  else {
+    $self->in_storage(0);
+    return $self;
+  }
+}
+
 
 =head2 throw_exception
 
-See Schema's throw_exception.
+See L<DBIx::Class::Schema/throw_exception>.
 
 =cut
 
 sub throw_exception {
   my $self=shift;
+
   if (ref $self && ref $self->result_source && $self->result_source->schema) {
-    $self->result_source->schema->throw_exception(@_);
-  } else {
-    croak(@_);
+    $self->result_source->schema->throw_exception(@_)
+  }
+  else {
+    DBIx::Class::Exception->throw(@_);
   }
 }
 
 =head2 id
 
+  my @pk = $row->id;
+
+=over
+
+=item Arguments: none
+
+=item Returns: A list of primary key values
+
+=back
+
 Returns the primary key(s) for a row. Can't be called as a class method.
 Actually implemented in L<DBIx::Class::PK>
 
 =head2 discard_changes
 
-Re-selects the row from the database, losing any changes that had
-been made.
+  $row->discard_changes
+
+=over
+
+=item Arguments: none
+
+=item Returns: nothing (updates object in-place)
+
+=back
+
+Retrieves and sets the row object data from the database, losing any
+local changes made.
 
 This method can also be used to refresh from storage, retrieving any
 changes made since the row was last read from storage. Actually
 implemented in L<DBIx::Class::PK>
 
+Note: If you are using L<DBIx::Class::Storage::DBI::Replicated> as your
+storage, please kept in mind that if you L</discard_changes> on a row that you
+just updated or created, you should wrap the entire bit inside a transaction.
+Otherwise you run the risk that you insert or update to the master database
+but read from a replicant database that has not yet been updated from the
+master.  This will result in unexpected results.
+
 =cut
 
 1;