Rails 3 ArgumentError：未知密钥：begin_date

Question

我有一个Waiver对象，其成员资格很多。我想弄清楚豁免是否有特定季度的会员资格：

def has_current_membership?
  memberships.count("begin_date >= :begin_date AND end_date <= :end_date", { :begin_date => Time.now.beginning_of_quarter, :end_date => Time.now.end_of_quarter }).count > 0
end

然而，这给了我ArgumentError: Unknown key: begin_date。但是，成员资格有一个begin_date列，因为如果我在控制台中执行Waiver.first.memberships，我会得到：

[#<Membership id: 20, waiver_id: 1, begin_date: "2011-10-01", end_date: "2012-01-01", created_at: "2011-11-19 07:10:10", updated_at: "2011-11-19 07:10:10">] 

我做错了什么？

Answer 1

您应该使用.where作为查找条件，而不是.count两次：

memberships.where("begin_date >= :begin_date AND end_date <= :end_date", { :begin_date => Time.now.beginning_of_quarter, :end_date => Time.now.end_of_quarter }).count > 0