ruby-on-rails - 如何在 Rails 4 中将 where 条件与 "or"链接起来？

Question

在我的 Rails 4 应用程序中，我需要查找所有计划，其间隔为月或 金额为0。

这不起作用:

class Plan < ActiveRecord::Base

  def self.by_interval(interval)
    where("interval = ? OR amount = ?", interval, 0)
  end

end

我收到此错误:

Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= 'month' OR amount = 0)  ORDER BY amount DESC' at line 1: SELECT `plans`.* FROM `plans`  WHERE (interval = 'month' OR amount = 0)  ORDER BY amount DESC

还有什么可能有效？

感谢您的帮助。

Answer 1

mysql中的'interval'是一个保留字(http://dev.mysql.com/doc/refman/5.6/en/reserved-words.html)。

尝试这样:

def self.by_interval(interval)
  where("`interval` = ? OR amount = ?", interval, 0)
end

注意“间隔”周围的反引号(不是引号)