Question

我有以下代码

def self.activate_lessons
i = 0
#for lesson in Lesson.to_activate
for lesson in Lesson.find :all, :conditions => ["start_date < ? AND (active <> ? OR active IS NULL)", DateTime.now, true]
  lesson.active = true
  lesson.save
  i += 1
  end
  i
end

这是一个vaild rails 4.2代码吗？

我收到了这个错误：

ActiveRecord::RecordNotFound: Couldn't find all Lessons with 'id': (all, {:conditions=>["start_date < ? AND (active <> ? OR active IS NULL)", Sat, 02 Apr 2016 09:50:06 +0000, true]}) (found 0 results, but was looking for 2)

Answer 1

如果您的目标是激活课程并返回已激活的课程数量，您可以这样做

def self.activate_lessons
 Lesson.where.not(active: true).where("start_date < ?", DateTime.now).update_all(active: true)
end

find（：first）和find（：all）支持从rails 3.2 +。
中删除

Answer 2

尝试使用此代码：

Lesson.where("start_date < ? AND active = ?", DateTime.now,Nil).update_all(active: true)

Rails 4.2有效代码与否？

2 个答案: