可以用Rail的ActiveRecord格式编写以下查询吗?我尝试了上亿种不同的方法来处理arel,但都不能得到相同的结果。
SELECT topic_id, count(*) as total
FROM questions_topics
WHERE question_id IN (
SELECT id
FROM questions
WHERE user_id = 1000
UNION ALL
SELECT questions.id
FROM questions JOIN answers ON (questions.id = answers.question_id)