Question

所以我跟随http://www.railstutorial.org/book，并且evrything在本地工作正常（运行sqlight3）。

尝试

时出现以下错误

heroku run rake db：migrate

这是错误消息的样子

运行rake db:migrate附加到终端...上，运行4049   迁移到AddPasswordDigestToUsers（20140817014655）   == 20140817014655 AddPasswordDigestToUsers：迁移=========================    - add_column（：users，：password_digest，：string）PG :: Error：ERROR：column＆＃34; password_digest＆＃34;关系＆＃34;用户＆＃34;已存在：ALTER   表＆＃34;用户＆＃34;添加栏目＆＃34; password_digest＆＃34;字符变化（255）耙   中止！ StandardError：发生错误，此错误以及稍后发生   迁移已取消：

PG ::错误：错误：列＆＃34; password_digest＆＃34;关系＆＃34;用户＆＃34;   已存在：ALTER TABLE＆＃34; users＆＃34;添加栏目＆＃34; password_digest＆＃34;   字符   变（255）/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in   exec' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in阻止执行＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract_adapter.rb:442:in block in log' /app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.8/lib/active_support/notifications/instrumenter.rb:20:in instrument＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract_adapter.rb:437:in log' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql/database_statements.rb:127:in执行＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/schema_statements.rb:360:in   add_column' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql/schema_statements.rb:395:in add_column＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:629:in   {_ 1}}阻止在say_with_time＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:601:in   block in method_missing' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:601:in的method_missing＆＃39;   /app/db/migrate/20140817014655_add_password_digest_to_users.rb:3:in   say_with_time' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:621:in exec_migration＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:559:in   change' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:575:in阻止迁移＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:294:in   block (2 levels) in migrate' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:558:in迁移＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:713:in   execute_migration_in_transaction＆＃39;中的with_connection' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:557:in阻止   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:1009:in   交易中migrate' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:963:in阻止＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in   block in ddl_transaction' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/database_statements.rb:203:in交易＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/transactions.rb:209:in within_new_transaction' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/database_statements.rb:203:in ddl_transaction＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:962:in   transaction' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:1009:in阻止迁移＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:920:in   execute_migration_in_transaction' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:924:in迁移＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:768:in   each' /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:920:in迁移＆＃39;   /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/railties/databases.rake:42:in   `块（2级）＆＃39;任务：TOP =＆gt; db：migrate（参见   使用--trace运行任务完全跟踪

我已经尝试过heroku pg：重置DATABASE_URL然后重试。还尝试将/ spec，/ lib，/ script，/ features，/ cucumber.yml添加到.slugignore

这就是我的架构：

up'
  /app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.8/lib/active_record/migration.rb:746:in

这就是我的密码摘要迁移看起来像

ActiveRecord::Schema.define(version: 20140818041701) do

  create_table "users", force: true do |t|
    t.string   "name"
    t.string   "email"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "password_digest"
    t.string   "remember_token"
    t.boolean  "admin",           default: false
  end

  add_index "users", ["email"], name: "index_users_on_email", unique: true
  add_index "users", ["remember_token"], name: "index_users_on_remember_token"

end

Answer 1

您的表格中已经有password_digest列，而迁移AddPasswordDigestToUsers您正在尝试创建另一个列，这就是创建问题的原因。删除迁移AddPasswordDigestToUsers，然后再次尝试运行rake db:migrate。在这种情况下，Sqlite3不会产生任何错误。如果您在迁移中编写intege而不是integer，则在使用sqlite时不会产生任何错误。

Answer 2

如果您只是删除密码摘要迁移文件，它将解决部署到heroku的短期问题，但随后协作者无法在本地下拉和设置其数据库。它们会遇到问题并可能会创建另一个迁移文件，从而产生同样的问题。

我不确定最佳解决方案，但到目前为止这似乎对我有用：

class AddPasswordDigestToUsers < ActiveRecord::Migration
  def change
    if Rails.env == "production"
    else
      add_column :users, :password_digest, :string   
    end
  end
end

尝试部署到heroku时出错（跟随ror教程）PG ::错误：错误：列＆＃34; password_digest＆＃34;关系＆＃34;用户＆＃34;已经存在

2 个答案: