将excel数据导入rails中的数据库

Question

我正在搜索将 excel 数据导入 mySQL 数据库。我参考“Ruby on Rails - Railscasts #396 Importing Csv And Excel”。随之而来的是，我得到了错误

dynamic constant assignment Subject = find_by(id: row["id"]) || new ^

谁能解释并给出解决方案。我的代码在 model.rb 中，

  def self.import(file)
allowed_attributes = [ "module_number", "module_name"]
Spreadsheet.client_encoding = 'UTF-8'
spreadsheet = open_spreadsheet(file.path)
header = spreadsheet.row(1)
(2..spreadsheet.last_row).each do |i|
  row = Hash[[header, spreadsheet.row(i)].transpose]
  subject = find_by(id: row["id"]) || new
  subject.attributes = row.to_hash.slice(*allowed_attributes)
  subject.save!
end

结束

 def self.open_spreadsheet(file)
case File.extname(file.original_filename)
  when ".csv" then
     Roo::Csv.new(file.path, nil, :ignore)
  when ".xls" then
    Roo::Excel.new(file.path, nil, :ignore)
  when ".xlsx" then
     Roo::Excelx.new(file.path, nil, :ignore)
  when ".xml" then
    Roo::XML.new(file.path, nil, :ignore)
else
  raise "Unknown file type: #{file.original_filename}"
end

结束

谢谢。

Answer 1

在 ruby​​ 中，常量以大写字符开头。你必须写subject 而不是Subject。在您的情况下，ruby 将 Subject 视为常量并抱怨更改常量。