如果你在法拉第请求的上下文中，你也可以只是传递params哈希作为第二个参数，法拉第会照顾到正确的param URL部分:

faraday_instance.get(url, params_hsh)

如果使用Ruby 1.9.2或更高版本，则可以使用URI。Encode_www_form如果你不需要数组。

例如(来自1.9.3的Ruby文档):

URI.encode_www_form([["q", "ruby"], ["lang", "en"]])
#=> "q=ruby&lang=en"
URI.encode_www_form("q" => "ruby", "lang" => "en")
#=> "q=ruby&lang=en"
URI.encode_www_form("q" => ["ruby", "perl"], "lang" => "en")
#=> "q=ruby&q=perl&lang=en"
URI.encode_www_form([["q", "ruby"], ["q", "perl"], ["lang", "en"]])
#=> "q=ruby&q=perl&lang=en"

您会注意到，数组值不是用包含[]的键名来设置的，就像我们在查询字符串中习惯的那样。encode_www_form使用的规范与HTML5对application/x-www-form-urlencoded data的定义一致。

我知道这是一个老问题，但我只是想张贴这段代码，因为我找不到一个简单的宝石来为我做这个任务。

module QueryParams

  def self.encode(value, key = nil)
    case value
    when Hash  then value.map { |k,v| encode(v, append_key(key,k)) }.join('&')
    when Array then value.map { |v| encode(v, "#{key}[]") }.join('&')
    when nil   then ''
    else            
      "#{key}=#{CGI.escape(value.to_s)}" 
    end
  end

  private

  def self.append_key(root_key, key)
    root_key.nil? ? key : "#{root_key}[#{key.to_s}]"
  end
end

在这里汇总为宝石:https://github.com/simen/queryparams

require 'uri'

class Hash
  def to_query_hash(key)
    reduce({}) do |h, (k, v)|
      new_key = key.nil? ? k : "#{key}[#{k}]"
      v = Hash[v.each_with_index.to_a.map(&:reverse)] if v.is_a?(Array)
      if v.is_a?(Hash)
        h.merge!(v.to_query_hash(new_key))
      else
        h[new_key] = v
      end
      h
    end
  end

  def to_query(key = nil)
    URI.encode_www_form(to_query_hash(key))
  end
end

2.4.2 :019 > {:a => "a", :b => "b"}.to_query_hash(nil)
 => {:a=>"a", :b=>"b"}

2.4.2 :020 > {:a => "a", :b => "b"}.to_query
 => "a=a&b=b"

2.4.2 :021 > {:a => "a", :b => ["c", "d", "e"]}.to_query_hash(nil)
 => {:a=>"a", "b[0]"=>"c", "b[1]"=>"d", "b[2]"=>"e"}

2.4.2 :022 > {:a => "a", :b => ["c", "d", "e"]}.to_query
 => "a=a&b%5B0%5D=c&b%5B1%5D=d&b%5B2%5D=e"

最好的方法是使用Hash。To_params可以很好地处理数组。

{a: 1, b: [1,2,3]}.to_param
"a=1&b[]=1&b[]=2&b[]=3"

对于基本的、非嵌套的散列，Rails/ActiveSupport有object# to_query。

>> {:a => "a", :b => ["c", "d", "e"]}.to_query
=> "a=a&b%5B%5D=c&b%5B%5D=d&b%5B%5D=e"
>> CGI.unescape({:a => "a", :b => ["c", "d", "e"]}.to_query)
=> "a=a&b[]=c&b[]=d&b[]=e"

http://api.rubyonrails.org/classes/Object.html#method-i-to_query