Documentation patch, related to joins, aliases and 'me'

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / ResultSet.pm

diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm
index 82109c9..13d0d76 100644 (file)
--- a/lib/DBIx/Class/ResultSet.pm
+++ b/lib/DBIx/Class/ResultSet.pm
@@ -95,14 +95,18 @@ sub new {
 
   $attrs->{alias} ||= 'me';
 
-  bless {
+  my $self = {
     result_source => $source,
     result_class => $attrs->{result_class} || $source->result_class,
     cond => $attrs->{where},
     count => undef,
     pager => undef,
     attrs => $attrs
-  }, $class;
+  };
+
+  bless $self, $class;
+
+  return $self;
 }
 
 =head2 search
@@ -281,6 +285,9 @@ If the C<key> is specified as C<primary>, it searches only on the primary key.
 If no C<key> is specified, it searches on all unique constraints defined on the
 source, including the primary key.
 
+If your table does not have a primary key, you B<must> provide a value for the
+C<key> attribute matching one of the unique constraints on the source.
+
 See also L</find_or_create> and L</update_or_create>. For information on how to
 declare unique constraints, see
 L<DBIx::Class::ResultSource/add_unique_constraint>.
@@ -296,7 +303,7 @@ sub find {
     ? $self->result_source->unique_constraint_columns($attrs->{key})
     : $self->result_source->primary_columns;
   $self->throw_exception(
-    "Can't find unless a primary key or unique constraint is defined"
+    "Can't find unless a primary key is defined or unique constraint is specified"
   ) unless @cols;
 
   # Parse out a hashref from input
@@ -559,7 +566,7 @@ sub _collapse_query {
 
   my $max_length = $rs->get_column('length')->max;
 
-Returns a ResultSetColumn instance for $column based on $self
+Returns a L<DBIx::Class::ResultSetColumn> instance for a column of the ResultSet.
 
 =cut
 
@@ -1337,7 +1344,7 @@ sub update_or_create {
   my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
   my $cond = ref $_[0] eq 'HASH' ? shift : {@_};
 
-  my $row = $self->find($cond);
+  my $row = $self->find($cond, $attrs);
   if (defined $row) {
     $row->update($cond);
     return $row;
@@ -1550,11 +1557,13 @@ sub _resolved_attrs {
 
   my $collapse = $attrs->{collapse} || {};
   if (my $prefetch = delete $attrs->{prefetch}) {
+    $prefetch = $self->_merge_attr({}, $prefetch);
     my @pre_order;
+    my $seen = $attrs->{seen_join} || {};
     foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) {
       # bring joins back to level of current class
       my @prefetch = $source->resolve_prefetch(
-        $p, $alias, { %{$attrs->{seen_join}||{}} }, \@pre_order, $collapse
+        $p, $alias, $seen, \@pre_order, $collapse
       );
       push(@{$attrs->{select}}, map { $_->[0] } @prefetch);
       push(@{$attrs->{as}}, map { $_->[1] } @prefetch);
@@ -1568,7 +1577,8 @@ sub _resolved_attrs {
 
 sub _merge_attr {
   my ($self, $a, $b) = @_;
-  return $b unless $a;
+  return $b unless defined($a);
+  return $a unless defined($b);
   
   if (ref $b eq 'HASH' && ref $a eq 'HASH') {
     foreach my $key (keys %{$b}) {
@@ -1799,6 +1809,19 @@ For example:
     }
   );
 
+You need to use the relationship (not the table) name in  conditions, 
+because they are aliased as such. The current table is aliased as "me", so 
+you need to use me.column_name in order to avoid ambiguity. For example:
+
+  # Get CDs from 1984 with a 'Foo' track 
+  my $rs = $schema->resultset('CD')->search(
+    { 
+      'me.year' => 1984,
+      'tracks.name' => 'Foo'
+    },
+    { join => 'tracks' }
+  );
+  
 If the same join is supplied twice, it will be aliased to <rel>_2 (and
 similarly for a third time). For e.g.