Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Browse files

Referencing a table via the ON condition in a join should force that …

…table to be eager-loaded via a JOIN rather than via subsequent queries.
  • Loading branch information...
commit cee3f9b36d01e6d54e0bd4c2fd06bee369bfff12 1 parent 5dc1fb3
@jonleighton jonleighton authored
View
13 activerecord/lib/active_record/relation.rb
@@ -407,8 +407,19 @@ def method_missing(method, *args, &block)
private
def references_eager_loaded_tables?
+ joined_tables = arel.join_sources.map do |join|
+ if join.is_a?(Arel::Nodes::StringJoin)
+ tables_in_string(join.left)
+ else
+ [join.left.table_name, join.left.table_alias]
+ end
+ end
+
+ joined_tables += [table.name, table.table_alias]
+
# always convert table names to downcase as in Oracle quoted table names are in uppercase
- joined_tables = (tables_in_string(arel.join_sql) + [table.name, table.table_alias]).compact.map{ |t| t.downcase }.uniq
+ joined_tables = joined_tables.flatten.compact.map { |t| t.downcase }.uniq
+
(tables_in_string(to_sql) - joined_tables).any?
end
View
15 activerecord/test/cases/relations_test.rb
@@ -850,4 +850,19 @@ def test_removing_limit_with_options
def test_primary_key
assert_equal "id", Post.scoped.primary_key
end
+
+ def test_eager_loading_with_conditions_on_joins
+ scope = Post.includes(:comments)
+
+ # This references the comments table, and so it should cause the comments to be eager
+ # loaded via a JOIN, rather than by subsequent queries.
+ scope = scope.joins(
+ Post.arel_table.create_join(
+ Post.arel_table,
+ Post.arel_table.create_on(Comment.arel_table[:id].eq(3))
+ )
+ )
+
+ assert scope.eager_loading?
+ end
end
Please sign in to comment.
Something went wrong with that request. Please try again.