ruby - Sinatra，数据映射器 : No such table errors

Question

不确定为什么我的日志中会出现此错误。这个错误经常发生，但不是一直发生，我不确定为什么。这是我的代码:

require 'rubygems'
require 'sinatra'

require 'data_mapper'
DataMapper::Logger.new($stdout, :debug)
DataMapper.setup(:default, 'sqlite3::memory:')

class LevelStatus
  include DataMapper::Resource
  property :id, Serial
  property :italian, Float
  property :hairbender, Float
  property :decaf, Float
end

DataMapper.finalize
LevelStatus.auto_migrate!

post '/update-levels' do
  @status = LevelStatus.create(
    :italian => params[:italian],
    :hairbender => params[:hairbender],
    :decaf => params[:decaf]
  )
  status 200
end

当我 POST 到 /update-levels 时，有时我会收到消息:

DataObjects::SyntaxError - no such table: level_statuses

导致此错误的代码有什么问题？

Answer 1

当然，线程池 SQLite 的实际行为，

但检查DataMapper documentation , section: 较少需要编写迁移

只需要允许 DataMapper 控制您的架构

DataMapper.auto_migrate!
DataMapper.auto_upgrade!