Question

我正在尝试启动和运行旧版Rails应用程序，当我执行此操作时 rake db：migrate

我得到以下内容：

arx_rails [master●] % rake db:migrate
==  AddSessionsTable: migrating ===============================================
-- create_table(:sessions)
rake aborted!
An error has occurred, all later migrations canceled:

Mysql2::Error: All parts of a PRIMARY KEY must be NOT NULL; if you need NULL in a key, use UNIQUE instead: CREATE TABLE `sessions` (`id` int(11) DEFAULT NULL auto_increment PRIMARY KEY, `session_id` varchar(255) NOT NULL, `data` text, `created_at` datetime NOT NULL, `updated_at` datetime NOT NULL) ENGINE=InnoDB/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:245:in `query'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:245:in `block in execute'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_adapter.rb:280:in `block in log'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_adapter.rb:275:in `log'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:245:in `execute'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/mysql2_adapter.rb:211:in `execute'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/schema_statements.rb:170:in `create_table'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:434:in `create_table'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:466:in `block in method_missing'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:438:in `block in say_with_time'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:438:in `say_with_time'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:458:in `method_missing'
/Users/steve/projects/asu/arx_rails/db/migrate/20120825213542_add_sessions_table.rb:3:in `change'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:407:in `block (2 levels) in migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:407:in `block in migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:123:in `with_connection'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:389:in `migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:528:in `migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:720:in `block (2 levels) in migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:777:in `call'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:777:in `ddl_transaction'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:719:in `block in migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:700:in `each'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:700:in `migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:570:in `up'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/migration.rb:551:in `migrate'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/railties/databases.rake:153:in `block (2 levels) in     <top (required)>'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/bin/ruby_executable_hooks:15:in `eval'
/Users/steve/.rvm/gems/ruby-1.9.3-p194/bin/ruby_executable_hooks:15:in `<main>'

迁移文件是：

class AddSessionsTable < ActiveRecord::Migration
  def change
    create_table :sessions do |t|
      t.string :session_id, :null => false
      t.text :data
      t.timestamps
    end

    add_index :sessions, :session_id
    add_index :sessions, :updated_at
  end
end

Rails总是创建id字段本身，而不必在迁移文件中明确编码，并且它使它成为主键但没有默认值。所以，我想知道它可能将id字段设置为新创建的表的DEFAULT为NULL。在一些我不知道的配置文件中？

有没有人见过这个？

Answer 1

看起来像Rails和MySQL的问题： https://github.com/rails/rails/pull/13247

在备注中，用户“ pjg ”表示以下内容：

使用Rails 2.3.5，MySQL版本5.7.9和mysql gem，你需要拥有这个位作为初始化器 config/initializers/abstract_mysql_adapter.rb：
class ActiveRecord::ConnectionAdapters::MysqlAdapter
  NATIVE_DATABASE_TYPES[:primary_key] = "int(11) auto_increment PRIMARY KEY"
end
对于mysql2应该是配置/初始化/ abstract_mysql2_adapter.rb：
class ActiveRecord::ConnectionAdapters::Mysql2Adapter
  NATIVE_DATABASE_TYPES[:primary_key] = "int(11) auto_increment PRIMARY KEY"
end

这可以解决问题吗？

（编辑：赞助解决方案提供商）

Answer 2

对于Rails 3.0.5的工作原理如下：

class ActiveRecord::ConnectionAdapters::ColumnDefinition
  def sql_type
    type.to_sym == :primary_key ? 'int(11) auto_increment PRIMARY KEY' :  base.type_to_sql(type.to_sym, limit, precision, scale) rescue type
  end 
end

Rails迁移错误，id默认为null

2 个答案: