Rails 3 ActiveRecord条件包括？

Question

我知道可以做到这一点：

Article.where("published_at <= ?", Time.now).includes(:comments)

但如果我只想在过去一个月发表评论怎么办？

.includes运算符是否允许条件？

Answer 1

Article.includes(:comments).where("articles.published_at <= ? and comments.created_at >= ?", Time.now, Time.now - 1.month)

编辑：

Article.joins(:comments).where("articles.published_at <= ? and comments.created_at >= ?", Time.now, Time.now - 1.month)

Answer 2

在Rails4中，它应该是： Article.includes(:comments).where("articles.published_at <= ? and comments.created_at >= ?", Time.now, Time.now - 1.month).references(:comments)

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