Rails，SQLException：没有这样的列

重新检查代码，重新启动计算机，然后运行rake db：migrate，我不知道还有什么可以做的。 我一直收到以下错误：

SQLite3::SQLException: no such column: uploads.user_id: SELECT COUNT(*) FROM "uploads" WHERE "uploads"."user_id" = 1 Extracted source (around line #12): 9:  10:  11: 
 12:  13: 
Uploads ()
 14: 
 15:  

这与has_many关联有什么关系吗？

show.html.erb

  
 
 
 
   
 
 
 
  
Uploads ()
 
  
   
  

upload.rb

 class Upload < ActiveRecord::Base attr_accessible :title belongs_to :user validates :title, presence: true validates :user_id, presence: true default_scope order: 'uploads.created_at DESC' end 

user.rb

 class User < ActiveRecord::Base attr_accessible :name, :email, :password, :password_confirmation has_secure_password has_many :uploads, dependent: :destroy before_save { |user| user.email = email.downcase } before_save :create_remember_token validates :name, presence: true, length: { maximum: 50 } VALID_EMAIL_REGEX = /\A[\w+\-.]+@[az\d\-.]+\.[az]+\z/i validates :email, presence: true, format: { with: VALID_EMAIL_REGEX }, uniqueness: { case_sensitive: false } validates :password, length: { minimum: 6 } validates :password_confirmation, presence: true private def create_remember_token self.remember_token = SecureRandom.urlsafe_base64 end end 

来自users_controller.rb

  def show @user = User.find(params[:id]) @uploads = @user.uploads.paginate(page: params[:page]) end 

20120524145724_create_uploads.rb

 class CreateUploads < ActiveRecord::Migration def self.up create_table :uploads do |t| t.string :title t.integer :user_id t.timestamps end add_index :uploads, [:user_id, :created_at] end def self.down drop_table :uploads end end 

Answer 1

运行迁移后，如果更新它，rails将不会重新运行它（它不知道您所做的更改）。

在编辑之前回滚迁移（rake db：rollback）或创建添加额外列的新迁移。

Answer 2

迁移可能会失败一些，如果你有一些错误，例如它不会工作。 确保它确实运行，你可以检查你的sqlite数据库，看看是否有user_id