• active_record/relation/from_clause
• active_record/relation/query_attribute
• active_record/relation/where_clause
• active_support/core_ext/array/wrap

• 模块 ActiveModel
• 模块 ActiveRecord
• 模块 ActiveRecord::Associations
• 模块 ActiveRecord::QueryMethods
• 模块 Arel
• 类 ActiveRecord::QueryMethods::WhereChain
• 类 ActiveRecord::Relation