1.try 永远不会抛出异常 在 没有的时候 返回 nil
province_id = Province.find_by_name(prov).try(:id)
2.find(:first, :condotions) 方法 不言而与
mobile_info = MobileInfo.find(:first, :conditions => ["mobile_num = ? ", mobile_num.to_i])
3.find(:all, :select, :conditions)
support_amount_a = ProvinceMerchantChangeValue.find(:all, :select => "DISTINCT change_value_id", :conditions => ["status = 1 and merchant_id = ? and province_id =? and channel_id in (select id from channels where status = 1)", merchant_id, province_id]).map { |cv| cv.change_value_id }.compact support_amount_s = ChangeValue.find(:all,:select => "price" ,:conditions => ["id in (?)", support_amount_a]) .map { |cv| cv.try(:price).to_i }.compact
4.发送post请求 能够在shell中运行
curl -d "channel=中信异度支付&action_type=娱人节-手机充值&user_indicate=13911731997&original_amount=10000" http://xx.xxx.xxx:3000/search.json
curl -d "channel=中信异度支付&action_type=娱人节-手机充值&user_indicate=13911731997&original_amount=10000" http://xx.xxx.xxx:3000/search.json |
5.Ruby 中纯数据结构 ( Struct 与 OpenStruct )
讲一下它俩之间的差别:
Struct 须要开头明白声明字段; 而 OpenStruct 人如其名,
随时能够加入属性
Struct 性能优秀; 而 OpenStruct 差点,
详细的性能差距可看这里:http://stackoverflow.com/questions/1177594/ruby-struct-vs-openstruct
Struct 是 Ruby 解释器内置, 用 C 实现; OpenStruct 是
Ruby 标准库, Ruby 实现
API 不同: Struct API 与 OpenStruct
6. MIme::Type.register
Mime::Type.register "application/json", :ejson
config/initializers/mime_types.rb
7.config/initializers/secure_problem_solved.rb
ActiveSupport::CoreExtensions::Hash::Conversions::XML_PARSING.delete(‘symbol‘) ActiveSupport::CoreExtensions::Hash::Conversions::XML_PARSING.delete(‘yaml‘)
8.config/initializers/new_rails_default.rb
if defined?(ActiveRecord) # Include Active Record class name as root for JSON serialized output. ActiveRecord::Base.include_root_in_json = true # Store the full class name (including module namespace) in STI type column. ActiveRecord::Base.store_full_sti_class = true end ActionController::Routing.generate_best_match = false # Use ISO 8601 format for JSON serialized times and dates. ActiveSupport.use_standard_json_time_format = true # Don‘t escape HTML entities in JSON, leave that for the #json_escape helper. # if you‘re including raw json in an HTML page. ActiveSupport.escape_html_entities_in_json = false
9.MemCacheStore 缓存
@_cache = ActiveSupport::Cache::MemCacheStore.new( CONFIG[‘host‘], { :namespace => "#{CONFIG[‘namespace‘]}::#{@name}" } ) localhost::callback_lock @_cache.write(pay_channel.channel_id,‘true’) v = @_cache.read(pay_channel.channel_id) if v.nil? || v != ‘true‘ return false else return true end end
10.联合索引
gem ‘composite_primary_keys‘, ‘6.0.1‘
https://github.com/momoplan
10.Hash assert_valid_keys 白名单
11.puma -C puma_service_qa.rb
12.pow
13. Time
start_time = start_time.to_s.to_datetime.at_beginning_of_day end_time = end_time.to_s.to_datetime.end_of_day
14.merchant.instance_of? MplusMerchant
m_order[:merchant_id] = (merchant.instance_of? MplusMerchant) ? merchant.id : merchant
15.will_paginate rails
安装之后须要改动config/environment.rb文件
在文件的最后加入:
require ‘will_paginate‘ 改动controller文件里的index方法: # @products = Product.find(:all) @products = Product.paginate :page => params[:page], :per_page => 2 .pagination = will_paginate @mplus_orders, :class => ‘digg_pagination‘ 最好有个include
16. # Excel Generator
gem ‘spreadsheet‘, ‘~> 0.7.3‘
PROVINCE = %w{ 安徽 北京 福建 甘肃 广东 广西 贵州 海南 河北 河南 黑龙江 湖北 湖南 吉林 江苏 江西 辽宁 内蒙古 宁夏 青海 山东 山西 陕西 上海 四川 天津 西藏 新疆 云南 浙江 重庆 } MONTH = 1.upto(12).to_a def self.total_to_xls(year = ‘2012‘, opts = {}) book = Spreadsheet::Workbook.new sheet1 = book.create_worksheet months = MONTH months = opts[:month].to_s.split(/,/) if opts[:month] fixed_row = months.collect{ |m| m.to_s + ‘月‘ }.insert(0, ‘‘) sheet1.row(0).concat(fixed_row) row1 = [‘‘] (months.size - 1).times { row1 << [‘用户数‘, ‘金额‘, ‘订单数‘] } sheet1.row(1).concat(row1.flatten!) row = 2 sheet1.row(row).insert(0, ‘全国‘) months.each_with_index do |m, i| sheet1.row(row).insert(i*3 + 1, self.monthly_users_count(m)) sheet1.row(row).insert(i*3 + 2, self.monthly_amount(m)) sheet1.row(row).insert(i*3 + 3, self.monthly_orders_count(m)) end PROVINCE.each do |province| row += 1 sheet1.row(row).insert(0, province) months.each_with_index do |m, i| sheet1.row(row).insert(i*3 + 1, self.monthly_users_count_by_province(m, province)) sheet1.row(row).insert(i*3 + 2, self.monthly_amount_by_province(m, province)) sheet1.row(row).insert(i*3 + 3, self.monthly_orders_count_by_province(m, province)) end end path = "tmp/phone_recharge.xls" book.write path path end
17. inject({})
selected_conditions = base_conditions.inject({}) do |hash, data| hash[data.first] = data.last unless data.last.blank? hash end
18.time_str.instance_of?
return time_str if time_str.instance_of? Time
19.Person.instance_eval
Person.instance_eval do def species "Homo Sapien" end end
20.class_eval
class Foo end metaclass = (class << Foo; self; end) metaclass.class_eval do def species "Homo Sapien" end end end
21.
Ruby中 respond_to? 和 send 的使用方法
http://galeki.is-programmer.com/posts/183.html
由于obj对象没法响应talk这个消息,假设使用 respond_to? 这种方法,就能够实现推断对象是否能响应给定的消息了
obj = Object.new
if obj.respond_to?("talk")
obj.talk
else
puts "Sorry,
object can‘t talk!"
end
request = gets.chomp
if book.respond_to?(request)
puts book.send(request)
else
puts "Input
error"
end
22.
method_missing,一个 Ruby 程序猿的梦中情人
def method_missing(method, *args) if method.to_s =~ /(.*)_with_cent$/ attr_name = $1 if self.respond_to?(attr_name) ‘%.2f‘ % (self.send(attr_name).to_f / 100.00) else super end end end
http://ruby-china.org/topics/3434
23.chomp
chomp方法是移除字符串尾部的分离符,比如\n,\r等...而gets默认的分离符是\n
24. hash.each_pair{|k,v|} & send()
if bank_order.present? data_hash.each_pair { |k, v| bank_order.send("#{k}=", v) } else bank_order = BankOrder.new data_hash end
25.config.middleware 通过 rake -T 能够查看, 在config/ - 去除不必的 middleware
26.1.day.ago.strftime(‘%Y%m%d’)