ruby on rails - Rake db:migrate not ignoring old migrations? -

running through michael hartl's known rails tutorial, hit snag.

i have in migration file, created rails generate model etc:

class createusers < activerecord::migration   def change     create_table :users |t|       t.string :name       t.string :email        t.timestamps     end   end end 

later, added second migration file:

class addindextousersemail < activerecord::migration   def change     add_index :users, :email, unique: true   end end 

to try , update database include new one, followed instructions , ran rake db:migrate, gives me error telling me i'm trying create table exists, i'm missing something.

am i...supposed delete first migration? wouldn't make sense. do?

(these files under db/migrate)

if realy want see migrations have been ran database, can inspect app database, there table called schema_migrations, in there can see unique id of each migration row example migration called: 20130402190449_add_flagand_table.rb, should see number 20130402190449 row of table, hope gave guidance