Question

我的数组category = ["Components for PC", "Soft", "OS"]
元素的数量可以有所不同创建这些数组元素Category（来自 .csv 文件）。在数组category中，我需要category[0]是父级，category[1] - 子级别，但是父级category[2]

PC的组件=＆gt; Soft =＆gt; OS

使用gem Ancestry

对于作品的两个元素这样的代码（虽然丑陋）：

last = nil

csv.each do |row| # rows from the table
  base = row[6].split('/')[0] # first element
  parent_category = Category.create!(name: base) if Category.where(name: base).first.nil? # Create a base category

  row[6].split('/').each do |category| # 
    if Category.where(name: category).first.nil? # if the category does not exist
      last = Category.create!(name: parent_category) if last == nil # create base Category
      # if the base exists, create her child
      child = Category.create!(name: category, ancestry: Category.where(name: base).first.id) if last != nil
    end
  end
end

如何为任意数量的元素创建类别和子类别？

Answer 1

假设您在categories中获得了一系列类别。

categories.each_with_index do |category, index|
  if index.zero? 
    parent = Category.create!(name: category)
  else
    Category.create!(name: category, ancestry: parent.id)
  end  
end

Answer 2

对于每个csv行：

获取一系列类别名称
获取根类别名称并将其从数组中删除
按名称

然后，对于数组中剩余的每个类别名称：

按名称
将类别设置为下一个类别的父级

csv.each do |row| # rows from the table
  category_names = row[6].split('/')

  root_category_name = category_names.shift

  parent_category = Category.find_or_create_by!(name: root_category_name) # Finds or creates the root category

  category_names.each do |category_name|
    parent_category = Category.find_or_create_by!(name: category_name, parent: parent_category) # Finds or creates the child category, which is the root for next categories
  end
end

祖先：如何从数组创建类别和子类别？

2 个答案: