Rails migration error with id default null

Question

I'm trying to get a legacy Rails app up and running and when I do a rake db:migrate

I get the following:

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>'

---

The migration file is:

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 has always created the id field itself without having to have it explicitly coded in the migration file and that it makes it a primary key but without a default value. So, I'm wondering where it might be setting the id fields to a DEFAULT of NULL for newly created tables. In some configuration file somewhere I don't know about?

Has anyone seen this before?

Answer 1

It looks like an issue with Rails and MySQL: https://github.com/rails/rails/pull/13247

In the notes, user " pjg " suggests the following:

With Rails 2.3.5, MySQL version 5.7.9 and mysql gem you need to have this bit as an initializer in config/initializers/abstract_mysql_adapter.rb :

 class ActiveRecord::ConnectionAdapters::MysqlAdapter NATIVE_DATABASE_TYPES[:primary_key] = "int(11) auto_increment PRIMARY KEY" end 

For mysql2 it should be config/initializers/abstract_mysql2_adapter.rb:

 class ActiveRecord::ConnectionAdapters::Mysql2Adapter NATIVE_DATABASE_TYPES[:primary_key] = "int(11) auto_increment PRIMARY KEY" end 

Does that resolve the issue?

(EDIT: giving credit to solution provider)

Answer 2

For Rails 3.0.5 works that way:

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

Answer 3

With Rails 4.0.6 works fine:

 config/initializers/abstract_mysql2_adapter.rb:

class ActiveRecord::ConnectionAdapters::Mysql2Adapter
  NATIVE_DATABASE_TYPES[:primary_key] = "int(11) NOT NULL auto_increment PRIMARY KEY"
end

$ gem list mysql

* LOCAL GEMS * mysql2 (0.3.18)