X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=3112cb51d6b8efda9eb26a73952142d601abd6db;hb=81e4dc3d93646a11bee973606a31be412f23cd5f;hp=71595e3ac386f7604a63147c2b54b1e313ae821d;hpb=2268474f6427676f69515a0ea47d638eaa6b497c;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index 71595e3..3112cb5 100644
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -207,11 +207,23 @@ 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
+=over
+
+=item WARNING
+
+If called on an object, proxies to L</new_result> instead, so
 
   my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
 
-will return a CD object, not a ResultSet.
+will return a CD object, not a ResultSet, and is equivalent to:
+
+  my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
+
+Please also keep in mind that many internals call C<new_result> directly,
+so overloading this method with the idea of intercepting new result object
+creation B<will not work>. See also warning pertaining to L</create>.
+
+=back
 
 =cut
 
@@ -1756,14 +1768,19 @@ sub _rs_update_delete {
   # simplify the joinmap and maybe decide if a grouping (and thus subquery) is necessary
   my $relation_classifications;
   if (ref($attrs->{from}) eq 'ARRAY') {
-    $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs);
-
-    $relation_classifications = $storage->_resolve_aliastypes_from_select_args (
-      [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
-      $attrs->{select},
-      $cond,
-      $attrs
-    ) unless $needs_group_by_subq;  # we already know we need a group, no point of resolving them
+    if (@{$attrs->{from}} == 1) {
+      # not a fucking JOIN at all, quit with the dickery
+      $relation_classifications = {};
+    } else {
+      $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs);
+
+      $relation_classifications = $storage->_resolve_aliastypes_from_select_args (
+        [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
+        $attrs->{select},
+        $cond,
+        $attrs
+      ) unless $needs_group_by_subq;  # we already know we need a group, no point of resolving them
+    }
   }
   else {
     $needs_group_by_subq ||= 1; # if {from} is unparseable assume the worst
@@ -1781,21 +1798,13 @@ sub _rs_update_delete {
   ) {
     # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
     # a condition containing 'me' or other table prefixes will not work
-    # at all. What this code tries to do (badly) is to generate a condition
-    # with the qualifiers removed, by exploiting the quote mechanism of sqla
-    #
-    # this is atrocious and should be replaced by normal sqla introspection
-    # one sunny day
-    my ($sql, @bind) = do {
-      my $sqla = $rsrc->storage->sql_maker;
-      local $sqla->{_dequalify_idents} = 1;
-      $sqla->_recurse_where($self->{cond});
-    } if $self->{cond};
-
+    # at all. Tell SQLMaker to dequalify idents via a gross hack.
+    my $sqla = $rsrc->storage->sql_maker;
+    local $sqla->{_dequalify_idents} = 1;
     return $rsrc->storage->$op(
       $rsrc,
       $op eq 'update' ? $values : (),
-      $self->{cond} ? \[$sql, @bind] : (),
+      $self->{cond},
     );
   }
 
@@ -2311,7 +2320,11 @@ Passes the hashref of input on to L<DBIx::Class::Row/new>.
 
 sub new_result {
   my ($self, $values) = @_;
-  $self->throw_exception( "new_result needs a hash" )
+
+  $self->throw_exception( "new_result takes only one argument - a hashref of values" )
+    if @_ > 2;
+
+  $self->throw_exception( "new_result expects a hashref" )
     unless (ref $values eq 'HASH');
 
   my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
@@ -2646,7 +2659,8 @@ it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
 lot of the internals simply never call it, so your override will be
 bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
 or L<insert|DBIx::Class::Row/insert> depending on how early in the
-L</create> process you need to intervene.
+L</create> process you need to intervene. See also warning pertaining to
+L</new>.
 
 =back
 
@@ -3482,7 +3496,6 @@ sub _resolved_attrs {
     $attrs->{_collapse_order_by} = \@$prefetch_ordering;
   }
 
-
   # if both page and offset are specified, produce a combined offset
   # even though it doesn't make much sense, this is what pre 081xx has
   # been doing
@@ -4003,6 +4016,12 @@ to Earth' and a cd with title 'Popular'.
 If you want to fetch related objects from other tables as well, see C<prefetch>
 below.
 
+ NOTE: An internal join-chain pruner will discard certain joins while
+ constructing the actual SQL query, as long as the joins in question do not
+ affect the retrieved result. This for example includes 1:1 left joins
+ that are not part of the restriction specification (WHERE/HAVING) nor are
+ a part of the query selection.
+
 For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
 
 =head2 prefetch
@@ -4231,6 +4250,24 @@ rows per page if the page attribute or method is used.
 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 software_limit
+
+=over 4
+
+=item Value: (0 | 1)
+
+=back
+
+When combined with L</rows> and/or L</offset> the generated SQL will not
+include any limit dialect stanzas. Instead the entire result will be selected
+as if no limits were specified, and DBIC will perform the limit locally, by
+artificially advancing and finishing the resulting L</cursor>.
+
+This is the recommended way of performing resultset limiting when no sane RDBMS
+implementation is available (e.g.
+L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
+L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
+
 =head2 group_by
 
 =over 4
@@ -4279,7 +4316,7 @@ attribute, this setting is ignored and an appropriate warning is issued.
 Adds to the WHERE clause.
 
   # only return rows WHERE deleted IS NULL for all searches
-  __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
+  __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
 
 Can be overridden by passing C<< { where => undef } >> as an attribute
 to a resultset.
@@ -4310,12 +4347,13 @@ L<DBIx::Class::Manual::Cookbook>.
 
 =over 4
 
-=item Value: ( 'update' | 'shared' )
+=item Value: ( 'update' | 'shared' | \$scalar )
 
 =back
 
 Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
-... FOR SHARED.
+... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
+query.
 
 =cut