Fixed a prefetch bug (o2m->prefetch_o2m+order_by+rows)

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / DBIHacks.pm

diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm
index 7576eb9..f5a03c9 100644 (file)
--- a/lib/DBIx/Class/Storage/DBIHacks.pm
+++ b/lib/DBIx/Class/Storage/DBIHacks.pm
@@ -23,10 +23,11 @@ use namespace::clean;
 # {from} specs, aiding the RDBMS query optimizer
 #
 sub _prune_unused_joins {
-  my ($self) = shift;
-
+  my $self = shift;
   my ($from, $select, $where, $attrs) = @_;
 
+  return $from unless $self->_use_join_optimizer;
+
   if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') {
     return $from;   # only standard {from} specs are supported
   }
@@ -100,31 +101,48 @@ sub _adjust_select_args_for_complex_prefetch {
     push @{$inner_attrs->{as}}, $attrs->{as}[$i];
   }
 
-  # construct the inner $from for the subquery
+  # construct the inner $from and lock it in a subquery
   # we need to prune first, because this will determine if we need a group_by below
   # the fake group_by is so that the pruner throws away all non-selecting, non-restricting
   # multijoins (since we def. do not care about those inside the subquery)
-  my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, {
-    group_by => ['dummy'], %$inner_attrs,
-  });
-
-  # if a multi-type join was needed in the subquery - add a group_by to simulate the
-  # collapse in the subq
-  $inner_attrs->{group_by} ||= $inner_select
-    if first { ! $_->[0]{-is_single} } (@{$inner_from}[1 .. $#$inner_from]);
-
-  # generate the subquery
-  my $subq = $self->_select_args_to_query (
-    $inner_from,
-    $inner_select,
-    $where,
-    $inner_attrs,
-  );
 
-  my $subq_joinspec = {
-    -alias => $attrs->{alias},
-    -source_handle => $inner_from->[0]{-source_handle},
-    $attrs->{alias} => $subq,
+  my $subq_joinspec = do {
+
+    # must use it here regardless of user requests
+    local $self->{_use_join_optimizer} = 1;
+
+    my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, {
+      group_by => ['dummy'], %$inner_attrs,
+    });
+
+    # if a multi-type join was needed in the subquery - add a group_by to simulate the
+    # collapse in the subq
+    if (
+      ! $inner_attrs->{group_by}
+        and
+      first { ! $_->[0]{-is_single} } (@{$inner_from}[1 .. $#$inner_from])
+    ) {
+      $inner_attrs->{group_by} = $self->_group_over_selection (
+        $inner_from, $inner_select, $inner_attrs->{order_by}
+      );
+    }
+
+    # we already optimized $inner_from above
+    local $self->{_use_join_optimizer} = 0;
+
+    # generate the subquery
+    my $subq = $self->_select_args_to_query (
+      $inner_from,
+      $inner_select,
+      $where,
+      $inner_attrs,
+    );
+
+    +{
+      -alias => $attrs->{alias},
+      -source_handle => $inner_from->[0]{-source_handle},
+      $attrs->{alias} => $subq,
+    };
   };
 
   # Generate the outer from - this is relatively easy (really just replace
@@ -156,7 +174,7 @@ sub _adjust_select_args_for_complex_prefetch {
     }
   }
 
-  # scan the from spec against different attributes, and see which joins are needed
+  # scan the *remaining* from spec against different attributes, and see which joins are needed
   # in what role
   my $outer_aliastypes =
     $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs );
@@ -304,10 +322,10 @@ sub _resolve_aliastypes_from_select_args {
     );
   }
 
-  # mark all join parents as mentioned
+  # mark all restricting/selecting join parents as such
   # (e.g.  join => { cds => 'tracks' } - tracks will need to bring cds too )
-  for my $type (keys %$aliases_by_type) {
-    for my $alias (keys %{$aliases_by_type->{$type}}) {
+  for my $type (qw/restricting selecting/) {
+    for my $alias (keys %{$aliases_by_type->{$type}||{}}) {
       $aliases_by_type->{$type}{$_} = 1
         for (map { values %$_ } @{ $alias_list->{$alias}{-join_path} || [] });
     }
@@ -316,6 +334,39 @@ sub _resolve_aliastypes_from_select_args {
   return $aliases_by_type;
 }
 
+sub _group_over_selection {
+  my ($self, $from, $select, $order_by) = @_;
+
+  my $rs_column_list = $self->_resolve_column_info ($from);
+
+  my (@group_by, %group_index);
+
+  for (@$select) {
+    if (! ref($_) or ref ($_) ne 'HASH' ) {
+      push @group_by, $_;
+      $group_index{$_}++;
+      if ($rs_column_list->{$_} and $_ !~ /\./ ) {
+        # add a fully qualified version as well
+        $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++;
+      }
+    }
+  }
+
+  # add any order_by parts that are not already present in the group_by
+  # we need to be careful not to add any named functions/aggregates
+  # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ]
+  for my $chunk ($self->_extract_order_columns($order_by)) {
+    # only consider real columns (for functions the user got to do an explicit group_by)
+    my $colinfo = $rs_column_list->{$chunk}
+      or next;
+
+    $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
+    push @group_by, $chunk unless $group_index{$chunk}++;
+  }
+
+  return \@group_by;
+}
+
 sub _resolve_ident_sources {
   my ($self, $ident) = @_;
 
@@ -520,8 +571,13 @@ sub _strip_cond_qualifiers {
     }
     else {
       foreach my $key (keys %$where) {
-        $key =~ /([^.]+)$/;
-        $cond->{$1} = $where->{$key};
+        if ($key eq '-or' && ref $where->{$key} eq 'ARRAY') {
+          $cond->{$key} = $self->_strip_cond_qualifiers($where->{$key});
+        }
+        else {
+          $key =~ /([^.]+)$/;
+          $cond->{$1} = $where->{$key};
+        }
       }
     }
   }