Rails范围为null还是空？

Question

我希望范围cancelled_at为空或空/空白的所有记录。

我发现很多帖子都要求IS NOT NULL /空/空白......但我需要相反。

我确信这很简单，但我很难过。

这是我目前得到的：

scope :active, where("cancelled_at IS NULL")

Answer 1

你试过吗？

 Patient.where("created_at IS NULL or CAST(created_at as text) = ''")
 # SELECT "patients".* FROM "patients" WHERE (created_at IS NULL or CAST(created_at as text) = '')