X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=7e59438a5026bdbe86410c2e5a978aaf6b4e01bf;hb=6bf3e3b3fa88b45f33ff21ae38239c69bd14335c;hp=19a71aa3a9ab60f59c7ca4d42bd8362e139cca54;hpb=a258ee5dacc4e7e3c748f59e8335a7688f5455d0;p=dbsrgits%2FDBIx-Class-Historic.git

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index 19a71aa..7e59438 100644
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -46,27 +46,13 @@ 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.
+A ResultSet also incorporates an implicit iterator. L</next> and L</reset>
+can be used to walk through 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
+L</find> L</next> L</all> L</first> L</single> L</count>
 
 =head1 EXAMPLES
 
@@ -674,7 +660,7 @@ L<DBIx::Class::Cursor> for more information.
 sub cursor {
   my ($self) = @_;
 
-  my $attrs = { %{$self->_resolved_attrs} };
+  my $attrs = $self->_resolved_attrs_copy;
   return $self->{cursor}
     ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
           $attrs->{where},$attrs);
@@ -725,7 +711,7 @@ sub single {
       $self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
   }
 
-  my $attrs = { %{$self->_resolved_attrs} };
+  my $attrs = $self->_resolved_attrs_copy;
   if ($where) {
     if (defined $attrs->{where}) {
       $attrs->{where} = {
@@ -1145,8 +1131,8 @@ sub result_class {
 =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.
+with to find the number of elements. Passing arguments is equivalent to
+C<< $rs->search ($cond, \%attrs)->count >>
 
 =cut
 
@@ -1155,10 +1141,11 @@ sub count {
   return $self->search(@_)->count if @_ and defined $_[0];
   return scalar @{ $self->get_cache } if $self->get_cache;
 
-  my @subq_attrs = qw/prefetch collapse group_by having/;
+  my @subq_attrs = qw/prefetch collapse distinct group_by having/;
+  my $attrs = $self->_resolved_attrs;
 
   # if we are not paged - we are simply asking for a limit
-  if (not $self->{attrs}{page} and not $self->{attrs}{software_limit}) {
+  if (not $attrs->{page} and not $attrs->{software_limit}) {
     push @subq_attrs, qw/rows offset/;
   }
 
@@ -1170,13 +1157,13 @@ sub count {
 sub _count_subq {
   my $self = shift;
 
-  my $attrs = { %{$self->_resolved_attrs} };
+  my $attrs = $self->_resolved_attrs_copy;
 
   # copy for the subquery, we need to do some adjustments to it too
   my $sub_attrs = { %$attrs };
 
-  # these can not go in the subquery either
-  delete $sub_attrs->{$_} for qw/prefetch select +select as +as columns +columns/;
+  # these can not go in the subquery, and there is no point of ordering it
+  delete $sub_attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns order_by/;
 
   # force a group_by and the same set of columns (most databases require this)
   $sub_attrs->{columns} = $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
@@ -1186,7 +1173,7 @@ sub _count_subq {
   }];
 
   # the subquery replaces this
-  delete $attrs->{$_} for qw/where bind prefetch collapse group_by having/;
+  delete $attrs->{$_} for qw/where bind prefetch collapse distinct group_by having having_bind/;
 
   return $self->__count ($attrs);
 }
@@ -1199,9 +1186,10 @@ sub _count_simple {
 
   # 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;
+  my $attrs = $self->_resolved_attrs;
+
+  $count -= $attrs->{offset} if $attrs->{offset};
+  $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
   $count = 0 if ($count < 0);
   return $count;
 }
@@ -1209,7 +1197,7 @@ sub _count_simple {
 sub __count {
   my ($self, $attrs) = @_;
 
-  $attrs ||= { %{$self->{attrs}} };
+  $attrs ||= $self->_resolved_attrs_copy;
 
   # take off any column specs, any pagers, record_filter is cdbi, and no point of ordering a count
   delete $attrs->{$_} for (qw/columns +columns select +select as +as rows offset page pager order_by record_filter/); 
@@ -1333,14 +1321,68 @@ sub first {
 }
 
 
-# _update_delete_via_subq
-#
-# Presence of some rs attributes requires a subquery to reliably
-# update/deletre
+# _rs_update_delete
 #
+# Determines whether and what type of subquery is required for the $rs operation.
+# If grouping is necessary either supplies its own, or verifies the current one
+# After all is done delegates to the proper storage method.
+
+sub _rs_update_delete {
+  my ($self, $op, $values) = @_;
+
+  my $rsrc = $self->result_source;
+
+  my $needs_group_by_subq = $self->_has_attr (qw/prefetch distinct join seen_join group_by/);
+  my $needs_subq = $self->_has_attr (qw/row offset page/);
+
+  if ($needs_group_by_subq or $needs_subq) {
+
+    # make a new $rs selecting only the PKs (that's all we really need)
+    my $attrs = $self->_resolved_attrs_copy;
+
+    delete $attrs->{$_} for qw/prefetch collapse select +select as +as columns +columns/;
+    $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->primary_columns) ];
+
+    if ($needs_group_by_subq) {
+      # make sure no group_by was supplied, or if there is one - make sure it matches
+      # the columns compiled above perfectly. Anything else can not be sanely executed
+      # on most databases so croak right then and there
+
+      if (my $g = $attrs->{group_by}) {
+        my @current_group_by = map
+          { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
+          (ref $g eq 'ARRAY' ? @$g : $g );
+
+        if (
+          join ("\x00", sort @current_group_by)
+            ne
+          join ("\x00", sort @{$attrs->{columns}} )
+        ) {
+          $self->throw_exception (
+            "You have just attempted a $op operation on a resultset which does group_by"
+            . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
+            . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
+            . ' kind of queries. Please retry the operation with a modified group_by or'
+            . ' without using one at all.'
+          );
+        }
+      }
+      else {
+        $attrs->{group_by} = $attrs->{columns};
+      }
+    }
+
+    my $subrs = (ref $self)->new($rsrc, $attrs);
 
-sub _update_delete_via_subq {
-  return $_[0]->_has_attr (qw/join seen_join group_by row offset page/);
+    return $self->result_source->storage->subq_update_delete($subrs, $op, $values);
+  }
+  else {
+    return $rsrc->storage->$op(
+      $rsrc,
+      $op eq 'update' ? $values : (),
+      $self->_cond_for_update_delete,
+    );
+  }
 }
 
 
@@ -1423,16 +1465,7 @@ sub update {
   $self->throw_exception('Values for update must be a hash')
     unless ref $values eq 'HASH';
 
-  # rs operations with subqueries are Storage dependent - delegate
-  if ($self->_update_delete_via_subq) {
-    return $self->result_source->storage->subq_update_delete($self, 'update', $values);
-  }
-
-  my $cond = $self->_cond_for_update_delete;
-
-  return $self->result_source->storage->update(
-    $self->result_source, $values, $cond
-  );
+  return $self->_rs_update_delete ('update', $values);
 }
 
 =head2 update_all
@@ -1487,15 +1520,7 @@ sub delete {
   $self->throw_exception('delete does not accept any arguments')
     if @_;
 
-  # rs operations with subqueries are Storage dependent - delegate
-  if ($self->_update_delete_via_subq) {
-    return $self->result_source->storage->subq_update_delete($self, 'delete');
-  }
-
-  my $cond = $self->_cond_for_update_delete;
-
-  $self->result_source->storage->delete($self->result_source, $cond);
-  return 1;
+  return $self->_rs_update_delete ('delete');
 }
 
 =head2 delete_all
@@ -2471,6 +2496,12 @@ sub _resolve_from {
   return ($from,$seen);
 }
 
+# too many times we have to do $attrs = { %{$self->_resolved_attrs} }
+sub _resolved_attrs_copy {
+  my $self = shift;
+  return { %{$self->_resolved_attrs (@_)} };
+}
+
 sub _resolved_attrs {
   my $self = shift;
   return $self->{_attrs} if $self->{_attrs};
@@ -2571,7 +2602,7 @@ sub _resolved_attrs {
 
   }
 
-  $attrs->{group_by} ||= $attrs->{select}
+  $attrs->{group_by} ||= [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ]
     if delete $attrs->{distinct};
   if ( $attrs->{order_by} ) {
     $attrs->{order_by} = (