X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBIHacks.pm;h=cbf462636ae2ced456bb862e68178d87b64e7147;hb=36fd7f073078f8f36277b467910ab68676361edf;hp=61f8aacc3185794f14982111ba86b0daadad6c38;hpb=e493ecb281730e358d23551d4addc5157b850892;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm
index 61f8aac..cbf4626 100644
--- a/lib/DBIx/Class/Storage/DBIHacks.pm
+++ b/lib/DBIx/Class/Storage/DBIHacks.pm
@@ -60,7 +60,7 @@ sub _adjust_select_args_for_complex_prefetch {
   my ($self, $from, $select, $where, $attrs) = @_;
 
   $self->throw_exception ('Nothing to prefetch... how did we get here?!')
-    if not @{$attrs->{_prefetch_select}};
+    if not @{$attrs->{_prefetch_selector_range}};
 
   $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
     if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY');
@@ -71,7 +71,7 @@ sub _adjust_select_args_for_complex_prefetch {
   delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/;
 
   my $inner_attrs = { %$attrs };
-  delete $inner_attrs->{$_} for qw/for collapse _prefetch_select _collapse_order_by select as/;
+  delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range _collapse_order_by select as/;
 
 
   # bring over all non-collapse-induced order_by into the inner query (if any)
@@ -88,7 +88,9 @@ sub _adjust_select_args_for_complex_prefetch {
   # on the outside we substitute any function for its alias
   my $outer_select = [ @$select ];
   my $inner_select = [];
-  for my $i (0 .. ( @$outer_select - @{$outer_attrs->{_prefetch_select}} - 1) ) {
+
+  my ($p_start, $p_end) = @{$outer_attrs->{_prefetch_selector_range}};
+  for my $i (0 .. $p_start - 1, $p_end + 1 .. $#$outer_select) {
     my $sel = $outer_select->[$i];
 
     if (ref $sel eq 'HASH' ) {
@@ -115,16 +117,30 @@ sub _adjust_select_args_for_complex_prefetch {
       group_by => ['dummy'], %$inner_attrs,
     });
 
-    # if a multi-type join was needed in the subquery - add a group_by to simulate the
-    # collapse in the subq
+    my $inner_aliastypes =
+      $self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs );
+
+    # if a multi-type non-selecting (only restricting) 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])
+      first {
+        $inner_aliastypes->{restricting}{$_}
+          and
+        ! $inner_aliastypes->{selecting}{$_}
+      } ( keys %{$inner_aliastypes->{multiplying}||{}} )
     ) {
-      $inner_attrs->{group_by} = $self->_group_over_selection (
+      my $unprocessed_order_chunks;
+      ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
         $inner_from, $inner_select, $inner_attrs->{order_by}
       );
+
+      $self->throw_exception (
+        'A required group_by clause could not be constructed automatically due to a complex '
+      . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable '
+      . 'group_by by hand'
+      )  if $unprocessed_order_chunks;
     }
 
     # we already optimized $inner_from above
@@ -183,6 +199,7 @@ sub _adjust_select_args_for_complex_prefetch {
   # also throw in a group_by if restricting to guard against
   # cross-join explosions
   #
+  my $need_outer_group_by;
   while (my $j = shift @$from) {
     my $alias = $j->[0]{-alias};
 
@@ -191,13 +208,28 @@ sub _adjust_select_args_for_complex_prefetch {
     }
     elsif ($outer_aliastypes->{restricting}{$alias}) {
       push @outer_from, $j;
-      $outer_attrs->{group_by} ||= $outer_select unless $j->[0]{-is_single};
+      $need_outer_group_by ||= ! $j->[0]{-is_single};
     }
   }
 
   # demote the outer_from head
   $outer_from[0] = $outer_from[0][0];
 
+  if ($need_outer_group_by and ! $outer_attrs->{group_by}) {
+
+    my $unprocessed_order_chunks;
+    ($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
+      \@outer_from, $outer_select, $outer_attrs->{order_by}
+    );
+
+    $self->throw_exception (
+      'A required group_by clause could not be constructed automatically due to a complex '
+    . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable '
+    . 'group_by by hand'
+    ) if $unprocessed_order_chunks;
+
+  }
+
   # This is totally horrific - the $where ends up in both the inner and outer query
   # Unfortunately not much can be done until SQLA2 introspection arrives, and even
   # then if where conditions apply to the *right* side of the prefetch, you may have
@@ -247,7 +279,11 @@ sub _resolve_aliastypes_from_select_args {
   # set up a botched SQLA
   my $sql_maker = $self->sql_maker;
 
-  local $sql_maker->{having_bind};  # these are throw away results
+  # these are throw away results, do not pollute the bind stack
+  local $sql_maker->{select_bind};
+  local $sql_maker->{where_bind};
+  local $sql_maker->{group_bind};
+  local $sql_maker->{having_bind};
 
   # we can't scan properly without any quoting (\b doesn't cut it
   # everywhere), so unless there is proper quoting set - use our
@@ -276,8 +312,8 @@ sub _resolve_aliastypes_from_select_args {
       }),
     ],
     selecting => [
-      $self->_extract_order_columns ($attrs->{order_by}, $sql_maker),
       $sql_maker->_recurse_fields ($select),
+      ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ),
     ],
   };
 
@@ -336,6 +372,7 @@ sub _resolve_aliastypes_from_select_args {
   return $aliases_by_type;
 }
 
+# This is the engine behind { distinct => 1 }
 sub _group_over_selection {
   my ($self, $from, $select, $order_by) = @_;
 
@@ -343,6 +380,9 @@ sub _group_over_selection {
 
   my (@group_by, %group_index);
 
+  # the logic is: if it is a { func => val } we assume an aggregate,
+  # otherwise if \'...' or \[...] we assume the user knows what is
+  # going on thus group over it
   for (@$select) {
     if (! ref($_) or ref ($_) ne 'HASH' ) {
       push @group_by, $_;
@@ -356,17 +396,28 @@ sub _group_over_selection {
 
   # 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($order_by)) {
+  # i.e. order_by => [ ... { count => 'foo' } ... ]
+  my @leftovers;
+  for ($self->_extract_order_criteria($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;
+    if (@$_ != 1) {
+      push @leftovers, $_;
+      next;
+    }
+    my $chunk = $_->[0];
+    my $colinfo = $rs_column_list->{$chunk} or do {
+      push @leftovers, $_;
+      next;
+    };
 
     $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
     push @group_by, $chunk unless $group_index{$chunk}++;
   }
 
-  return \@group_by;
+  return wantarray
+    ? (\@group_by, (@leftovers ? \@leftovers : undef) )
+    : \@group_by
+  ;
 }
 
 sub _resolve_ident_sources {
@@ -588,7 +639,7 @@ sub _strip_cond_qualifiers {
   return $cond;
 }
 
-sub _extract_order_columns {
+sub _extract_order_criteria {
   my ($self, $order_by, $sql_maker) = @_;
 
   my $parser = sub {
@@ -598,8 +649,9 @@ sub _extract_order_columns {
       unless wantarray;
 
     my @chunks;
-    for my $chunk (map { ref $_ ? @$_ : $_ } ($sql_maker->_order_by_chunks ($order_by) ) ) {
-      $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
+    for ($sql_maker->_order_by_chunks ($order_by) ) {
+      my $chunk = ref $_ ? $_ : [ $_ ];
+      $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
       push @chunks, $chunk;
     }