数据库表代码如下class CreateGzsAdmins < ActiveRecord::Migration def self.up create_table :gzs_admins do |t| t.string :username t.string :hashed_password t.integer :logins t.string :loginIP t.timestamps end GzsAdmin.create(:username => "admin", :hashed_password => "8c6976e5b5410415bde908bd4dee15dfb167a9c873fc4bb8a81f6f2ab448a918 ", :logins => 0, :loginIP => "" ) end def self.down drop_table :gzs_admins endend其中 GzsAdmin.create(:username => "admin", :hashed_password => "8c6976e5b5410415bde908bd4dee15dfb167a9c873fc4bb8a81f6f2ab448a918 ", :logins => 0, :loginIP => "" )未执行，而其他表中的这类代码可以执行并创建数据，这是为什么？