X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBIHacks.pm;h=ba1faa486776270fa0c66da9075e5837a0226ddf;hb=14e26c5f3516e39d9191ca9b2a9d460f8f495654;hp=d4a9df844c709ee05ea0bbc27254d3389b2015b8;hpb=d2fcb9b3612958ecc794acae77520f3da06d3c5b;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBIHacks.pm b/lib/DBIx/Class/Storage/DBIHacks.pm
index d4a9df8..ba1faa4 100644
--- 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
   }
@@ -37,7 +38,6 @@ sub _prune_unused_joins {
   # {multiplying} joins can go
   delete $aliastypes->{multiplying} if $attrs->{group_by};
 
-
   my @newfrom = $from->[0]; # FROM head is always present
 
   my %need_joins = (map { %{$_||{}} } (values %$aliastypes) );
@@ -101,27 +101,62 @@ 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
-  my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, $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,
-  );
+  # 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 $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,
+    });
+
+    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 {
+        $inner_aliastypes->{restricting}{$_}
+          and
+        ! $inner_aliastypes->{selecting}{$_}
+      } ( keys %{$inner_aliastypes->{multiplying}||{}} )
+    ) {
+      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;
+    }
 
-  my $subq_joinspec = {
-    -alias => $attrs->{alias},
-    -source_handle => $inner_from->[0]{-source_handle},
-    $attrs->{alias} => $subq,
+    # 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
@@ -134,14 +169,13 @@ sub _adjust_select_args_for_complex_prefetch {
   # - it is part of the restrictions, in which case we need to collapse the outer
   #   result by tackling yet another group_by to the outside of the query
 
-  # normalize a copy of $from, so it will be easier to work with further
-  # down (i.e. promote the initial hashref to an AoH)
   $from = [ @$from ];
-  $from->[0] = [ $from->[0] ];
 
   # so first generate the outer_from, up to the substitution point
   my @outer_from;
   while (my $j = shift @$from) {
+    $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH
+
     if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap
       push @outer_from, [
         $subq_joinspec,
@@ -154,7 +188,7 @@ 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 );
@@ -218,7 +252,7 @@ sub _resolve_aliastypes_from_select_args {
 
     $alias_list->{$al} = $j;
     $aliases_by_type->{multiplying}{$al} = 1
-      unless $j->{-is_single};
+      if ref($_) eq 'ARRAY' and ! $j->{-is_single}; # not array == {from} head == can't be multiplying
   }
 
   # get a column to source/alias map (including unqualified ones)
@@ -227,7 +261,9 @@ 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->{having_bind};
+  local $sql_maker->{select_bind};
 
   # we can't scan properly without any quoting (\b doesn't cut it
   # everywhere), so unless there is proper quoting set - use our
@@ -239,7 +275,9 @@ sub _resolve_aliastypes_from_select_args {
   local $sql_maker->{name_sep} = $sql_maker->{name_sep};
 
   unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
-    $sql_maker->{quote_char} = "\x00";
+    $sql_maker->{quote_char} = ["\x00", "\xFF"];
+    # if we don't unset it we screw up retarded but unfortunately working
+    # 'MAX(foo.bar)' => { '>', 3 }
     $sql_maker->{name_sep} = '';
   }
 
@@ -254,8 +292,8 @@ 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) ),
     ],
   };
 
@@ -302,10 +340,10 @@ 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} || [] });
     }
@@ -314,6 +352,51 @@ 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) = @_;
+
+  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. 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)
+    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 wantarray
+    ? (\@group_by, (@leftovers ? \@leftovers : undef) )
+    : \@group_by
+  ;
+}
+
 sub _resolve_ident_sources {
   my ($self, $ident) = @_;
 
@@ -358,7 +441,7 @@ sub _resolve_column_info {
   my ($self, $ident, $colnames) = @_;
   my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident);
 
-  my (%return, %seen_cols, @auto_colnames);
+  my (%seen_cols, @auto_colnames);
 
   # compile a global list of column names, to be able to properly
   # disambiguate unqualified column names (if at all possible)
@@ -375,25 +458,23 @@ sub _resolve_column_info {
     grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols),
   ];
 
-  COLUMN:
+  my (%return, $colinfos);
   foreach my $col (@$colnames) {
-    my ($alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x;
+    my ($source_alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x;
 
-    unless ($alias) {
-      # see if the column was seen exactly once (so we know which rsrc it came from)
-      if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1) {
-        $alias = $seen_cols{$colname}[0];
-      }
-      else {
-        next COLUMN;
-      }
-    }
+    # if the column was seen exactly once - we know which rsrc it came from
+    $source_alias ||= $seen_cols{$colname}[0]
+      if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1);
 
-    my $rsrc = $alias2src->{$alias};
-    $return{$col} = $rsrc && {
-      %{$rsrc->column_info($colname)},
+    next unless $source_alias;
+
+    my $rsrc = $alias2src->{$source_alias}
+      or next;
+
+    $return{$col} = {
+      %{ ( $colinfos->{$source_alias} ||= $rsrc->columns_info )->{$colname} },
       -result_source => $rsrc,
-      -source_alias => $alias,
+      -source_alias => $source_alias,
     };
   }
 
@@ -518,8 +599,13 @@ 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};
+        }
       }
     }
   }
@@ -530,7 +616,7 @@ sub _strip_cond_qualifiers {
   return $cond;
 }
 
-sub _extract_order_columns {
+sub _extract_order_criteria {
   my ($self, $order_by, $sql_maker) = @_;
 
   my $parser = sub {
@@ -540,8 +626,9 @@ 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;
     }