creation_date as created_at, 'answer' as type, title, body, owner_user_id, cast(parent_id as string) as parent_id from foobar_posts_answers where creation_date >= timestamp("2022-01-01") ), posts_questions as ( select id as post_id, creation_date as created_at, 'question' as type, title, body, owner_user_id, parent_id from hogehoge_posts_questions where creation_date >= timestamp("2022-01-01") ), user_group_foo as (