您尝试解决错误问题的方法有些偏离。您正在尝试构建一个传递给ActiveRecord的字符串，以便在您仅应尝试构建查询时就可以构建一个查询。

Your approach is a little off as you're trying to solve the wrong problem. You're trying to build a string to hand to ActiveRecord so that it can build a query when you should simply be trying to build a query.

：

Model.where('a and b')

这与说的一样：

Model.where('a').where('b')

，您可以说：

Model.where('c like ?', pattern)

而不是：

Model.where("c like '#{pattern}'")

将这两个想法与您的 self.instance_values 结合起来>您可能会得到类似的内容

Combining those two ideas with your self.instance_values you could get something like:

def query
  self.instance_values.select { |_, v| v.present? }.inject(YourModel) do |q, (name, value)|
    q.where("#{name} like ?", "%#{value}%")
  end
end

甚至：

def query
  empties      = ->(_, v) { v.blank? }
  add_to_query = ->(q, (n, v)) { q.where("#{n} like ?", "%#{v}%") }
  instance_values.reject(&empties)
                 .inject(YourModel, &add_to_query)
end

那些假设您已经正确地将所有实例变量列入了白名单。如果还没有，那么应该。

Those assume that you've properly whitelisted all your instance variables. If you haven't then you should.