task :migrate_accounts_schema => [:environment] do |t|
  users = User.find :all,:conditions => ["state = 2"],:order => "id asc"
  users.each do |user|            
    if user.state == 2
      ActiveRecord::Base.establish_connection(
        :adapter  => "postgresql",:host     => user.database_host,:port     => user.database_port,:username => user.subdomain,:password => "#{user.database_password}",:database => user.database_name
      )
      Rake::Task["db:migrate"].invoke
    end
  end
end

问题是任务执行db：仅迁移用户[0]用户(集合中的第一个用户),并且没有错误,只是静静地停止…

这是rake –trace的输出

** Invoke app:migrate_accounts_schema (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute app:migrate_accounts_schema    
** Invoke db:migrate (first_time)
** Invoke environment 
** Execute db:migrate
** Invoke db:schema:dump (first_time)
** Invoke environment 
** Execute db:schema:dump
** Invoke db:migrate

我不知道为什么其他用户不能迁移.