Rails - 使用回形针图像播种

Question

我发现了几个关于该主题的问题，并按照说明为我的模型播种图像。但是，播种时我收到错误 "PG::UndefinedColumn: ERROR: column meals.meal_avatar does not exist"，即使我的模型有错误。这是我的膳食模型

class Meal < ActiveRecord::Base
  has_attached_file :meal_avatar, styles: { large: '300x300' }, default_url: '/images/:style/missing.png'
  validates_attachment_content_type :meal_avatar, content_type: /\Aimage\/.*\Z/
end

这是迁移

  def self.up
    change_table :meals do |t|
      t.attachment :meal_avatar
    end
  end

控制器允许的参数

  def meal_params
    params.require(:meal).permit(:name, :meal_avatar)
  end

我播种图像的方式（断章取义，但你可以理解）

meal_seed = [
  {
    name: "Salad",
    meal_avatar: File.new("app/assets/images/salad.jpg")
  }
]
meal_seed.each do |meal_params|
  meal = category.meals.find_or_create_by(meal_params)
end

知道为什么我的种子失败了:?谢谢！

Answer 1

这与 find_or_create_by 有关。我相信这个发现发生在回形针对象被处理之前，这就是为什么它试图寻找列 meal_avatar.

将它们分成两行。

meal_seed.each do |meal_params|
  avatar = meal_params.delete(:meal_avatar)
  meal = category.meals.find_or_initialize_by(meal_params)
  meal.meal_avatar = avatar

  meal.save
end

Answer 2

试试这个，它可能适合你！

meal_seed.each_with_index do |meal_params, index|
  Meal.create!(meal_params)  
end

Rails - 使用回形针图像播种

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