Question

我正在寻找一种更干的方法来迭代一些代码。我有一个User模型，我希望在Users模型中保留一定数量的ReportRecord（用于报告）。

我有一个我要记录的User.names值的已定义列表（即＆＃34; Jan＆＃34;，＆＃34; Lisa＆＃34;，＆＃34; Tina＆＃34;）。如何使这个代码更干，因为列表比三个值长得多？

@users = User.all
@users.each do |u|

  # this part repeats with different names
  quantity = u.where("name = ?", "Jan").count
  ReportRecord.create(:user_id => u.id, :name => "Jan", :quantity => quantity)

  # repeated code with different name
  quantity = u.where("name = ?", "Lisa").count
  ReportRecord.create(:user_id => u.id, :name => "Lisa", :quantity => quantity)

  # repeated code with different name
  quantity = u.where("name = ?", "Tina").count
  ReportRecord.create(:user_id => u.id, :name => "Tina", :quantity => quantity)

end

Answer 1

我会先对所有用户求和（1个查询而不是3个）：

git pull

Answer 2

names = %w(Jan List Tina)

names.each do |name|
  count = User.where(name: name).count
  ReportRecord.create(name: name, quantity: count) # I don't understand `u.id`
end

Rails - 通过多个数组迭代

2 个答案: