Merge pull request #15803 from sgrif/sg-column-in-associations

Don't rely on the column for type casting reflections

activerecord/lib/active_record/associations/collection_association.rb

@@ -55,9 +55,9 @@ def ids_reader
 
       # Implements the ids writer method, e.g. foo.item_ids= for Foo.has_many :items
       def ids_writer(ids)
-        pk_column = reflection.primary_key_column
+        pk_type = reflection.primary_key_type
         ids = Array(ids).reject { |id| id.blank? }
-        ids.map! { |i| pk_column.type_cast_from_user(i) }
+        ids.map! { |i| pk_type.type_cast_from_user(i) }
         replace(klass.find(ids).index_by { |r| r.id }.values_at(*ids))
       end
 

activerecord/lib/active_record/reflection.rb

@@ -290,8 +290,8 @@ def foreign_key
         @foreign_key ||= options[:foreign_key] || derive_foreign_key
       end
 
-      def primary_key_column
-        klass.columns_hash[klass.primary_key]
+      def primary_key_type
+        klass.type_for_attribute(klass.primary_key)
       end
 
       def association_foreign_key

activerecord/lib/active_record/validations/uniqueness.rb

@@ -48,7 +48,7 @@ def find_finder_class_for(record) #:nodoc:
       def build_relation(klass, table, attribute, value) #:nodoc:
         if reflection = klass._reflect_on_association(attribute)
           attribute = reflection.foreign_key
-          value = value.attributes[reflection.primary_key_column.name] unless value.nil?
+          value = value.attributes[reflection.klass.primary_key] unless value.nil?
         end
 
         attribute_name = attribute.to_s