Question

我尝试＆＃34; rake db：rollback STEP = 6＆＃34;或者更多，但当我运行＆＃34; rake db：migrate＆＃34;它只显示正在执行的最后一个迁移文件：

== 20150508040222 CreateStructure：迁移================================== == 20150508040222 CreateStructure：已迁移（0.0000s）=========================

当我尝试使用＆＃34; rails console＆＃34;检查上一步中是否已创建新字段时和＆＃34;放置User.new（）。inspect＆＃34;它显示那些字段仍然缺失。

如何回滚以便执行我编辑过的那些交易文件？

[编辑]

当我尝试使用＆＃34; rake db：migrate VERSION = 20150328013052＆＃34;回滚时，它在上次第二次迁移时失败，因为它无法删除不存在的字段。我认为我已经修改了迁移以在迁移已经执行后添加这些字段，因此这些字段不存在。我该怎么办？我尝试修改schema.rb中的时间戳并运行migrate，但看起来并不是跟踪当前版本的内容。

class AddLoginToUsers < ActiveRecord::Migration
  def change
    add_column :name, :password, :string
  end
end

== 20150508040222 CreateStructure：还原==================================   == 20150508040222 CreateStructure：reverted（0.0273s）=========================

== 20150506210153 AddLoginToUsers：还原==================================    - remove_column（：name，：password，：string）rake aborted！ StandardError：发生错误，此错误以及稍后的所有迁移   取消：

无法找到表格   ＆＃39; name＆＃39; /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:517:in table_structure' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:431:in primary_key＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:538:in copy_table' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:533:in move_table＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:526:in block in alter_table' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in transaction＆＃39;   在/ {/ 1 /} / {   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:662:in   {_ 1}}阻止在say_with_time＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:632:in   alter_table' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/sqlite3_adapter.rb:467:in的method_missing＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:497:in   block in method_missing' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:632:in各＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:496:in   say_with_time' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:652:in exec_migration＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:590:in   block in revert' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:496:in阻止迁移＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in   revert' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:604:in迁移＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:765:in   execute_migration_in_transaction＆＃39;中的block (2 levels) in migrate' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:589:in阻止   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:1041:in   交易中with_connection' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:588:in阻止＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/transaction.rb:188:in   migrate' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:995:in交易＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/transactions.rb:220:in block in ddl_transaction' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in ddl_transaction＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:994:in   within_new_transaction' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in阻止迁移＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:952:in   transaction' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:1041:in迁移＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:827:in   execute_migration_in_transaction' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:956:in迁移＆＃39;   /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/tasks/database_tasks.rb:137:in   each' /var/lib/gems/1.9.1/gems/activerecord-4.2.0/lib/active_record/migration.rb:952:in阻止（2级）＆＃39;任务：TOP =＆gt; db：migrate（参见   使用--trace运行任务完全跟踪

[编辑]

好的，我知道，我只需要删除迁移以反转它们，然后重写它们。问题解决了。

Answer 1

我会通过打开schema.rb文件（位于db / schema.rb中）找到Schema的当前状态，第一行看起来像：

ActiveRecord::Schema.define(version: 20150507210038) do

将该版本号与db / migrate文件夹中的迁移相匹配。也许您已经进行了适当的迁移。要恢复迁移，我建议：

rake db:migrate VERSION=20080906120000

版本号对应于迁移文件名的版本。

<强> [UPDATE]

错误在于：

class AddLoginToUsers < ActiveRecord::Migration
  def change
   add_column :name, :password, :string
  end
end

add_column具有以下要求：

add_column :table, :column_name, :column_type

确保表格是多元的。检查Schema.rb文件以查看表。由于这是users表，也许你的意思是：

add_column :users, :password, :string

如果您遇到架构问题，可以完全转储数据库并重新创建它。我将编辑适当的迁移（删除导致问题的迁移），然后通过运行转储并重新创建数据库：

rake db:drop db:create db:migrate

然后，您可以运行另一次迁移以添加新列。您可以在重新创建数据库之前将这些添加到现有迁移中。希望有所帮助。

Ruby rails rake不能回滚得足够

1 个答案: