# Error after rake migrate:db **URL:** \ **Category:** Rails\ **Created:** [September 20, 2007, 2:22am UTC](https://www.ruby-forum.com/t/error-after-rake-migrate-db/115040 "2007-09-20T02:22:44Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![mike343](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/58f4c7/32.png) [@mike343](https://www.ruby-forum.com/u/mike343)\ **Post date:** [September 20, 2007, 2:22am UTC](https://www.ruby-forum.com/t/error-after-rake-migrate-db/115040/1 "2007-09-20T02:22:44Z")
I’m getting the error Mysql::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘(11), `first_name` varchar(255) DEFAULT NULL, `last_name` varchar(255) DEFAULT N’ at line 1: CREATE TABLE undergraduates (`id` int(11) DEFAULT NULL auto\_increment PRIMARY KEY(11), `first_name` varchar(255) DEFAULT NULL, `last_name` varchar(255) DEFAULT NULL) ENGINE=InnoDB and I used --trace and it found /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/connection\_adapters/abstract\_adapter.rb:128:in `log' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb:243:in`execute’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/connection\_adapters/abstract/schema\_statements.rb:104:in `create_table' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb:353:in`create\_table’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:275:in `send' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/migration.rb:275:in`method\_missing’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:259:in `say_with_time' /usr/lib/ruby/1.8/benchmark.rb:293:in`measure’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:259:in `say_with_time' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/migration.rb:273:in`method\_missing’ ./db/migrate//003\_create\_undergraduates.rb:3:in `real_up' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/migration.rb:212:in`send’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:212:in `migrate' /usr/lib/ruby/1.8/benchmark.rb:293:in`measure’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:212:in `migrate' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/migration.rb:335:in`migrate’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:330:in `each' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/migration.rb:330:in`migrate’ /home/michael/work/student/config/…/vendor/rails/activerecord/lib/active\_record/migration.rb:297:in `up' /home/michael/work/student/config/../vendor/rails/activerecord/lib/active_record/migration.rb:288:in`migrate’ /home/michael/work/student/config/…/vendor/rails/railties/lib/tasks/databases.rake:4 /usr/lib/ruby/1.8/rake.rb:387:in `call' /usr/lib/ruby/1.8/rake.rb:387:in`execute’ /usr/lib/ruby/1.8/rake.rb:387:in `each' /usr/lib/ruby/1.8/rake.rb:387:in`execute’ /usr/lib/ruby/1.8/rake.rb:357:in `invoke' /usr/lib/ruby/1.8/rake.rb:350:in`synchronize’ /usr/lib/ruby/1.8/rake.rb:350:in `invoke' /usr/lib/ruby/1.8/rake.rb:1924:in`run’ /usr/lib/ruby/1.8/rake.rb:1924:in `each' /usr/lib/ruby/1.8/rake.rb:1924:in`run’ /usr/bin/rake:4 I wasn’t sure whether the method missing is the reason behind the error… and I’m not really sure what to do if it is (just learning rails for a class at UC Berkeley). Any help would be appreciated! Thanks Michael ---
**Author:** ![mike343](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/58f4c7/32.png) [@mike343](https://www.ruby-forum.com/u/mike343)\ **Post date:** [September 20, 2007, 3:42am UTC](https://www.ruby-forum.com/t/error-after-rake-migrate-db/115040/2 "2007-09-20T03:42:44Z")
OK, figured it out. Apparently MYSQL doesn’t like it when you try to add an “id” as “id”. Michael ---
**Author:** ![mike343](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/58f4c7/32.png) [@mike343](https://www.ruby-forum.com/u/mike343)\ **Post date:** [September 20, 2007, 6:04am UTC](https://www.ruby-forum.com/t/error-after-rake-migrate-db/115040/3 "2007-09-20T06:04:23Z")
Michael Mike wrote: > OK, figured it out. Apparently MYSQL doesn’t like it when you try to add > an “id” as “id”. > > Michael When having rake db:migrate errors, sending the code for the migration that it’s choking on helps us too… But let’s take your problem and discovered solution a step further. Primary key fields are created by default in your migration by Rails. They are, also by default, named “id”. Any field that is a combination of a table name, an underscore and the string “id” will be seen as a foreign key to Rails. Ex. Let’s assume a person owns many things, but a thing can only be owned by 1 person… simplistic but a decent example I think. Imagine your migrations have these. 001\_create\_people.rb class CreatePeople \< ActiveRecord::Migration def self.up create\_table :people do |t| t.column :name, :string, :null =\> false; end end def self.down drop\_table :people end end This creates the following table. (id is created automatically and tagged as a primary auto increment key) People Table -=-=-=-=-=-=-= id name 002\_create\_things.rb class CreateThings \< ActiveRecord::Migration def self.up create\_table :things do |t| t.column :people\_id, :integer, :null =\> false; t.column :description :strig, :null =\> false; end end def self.down drop\_table :things end end Creates this with again id done automatically… Things Table. -=-=-=-=-=-=-=- id description people\_id If you have your model defined as (1 to many relationship)… and this is actual complete and valid code. (Just untested lol) class Person \< ActiveRecord::Base has\_many :things end class Thing \< ActiveRecord::Base belongs\_to :person end This uses the named field ( people.id -\> things.people\_id ) in your migration and the relationship mapping (has\_many / belongs\_to) in your models to know the primary key and foreign key pairs. Let’s assume each table has this data: People Table data. id: 1 name: John Things Table data. (2 rows) id: 1 people\_id: 1 description: “A car” id: 2 people\_id: 1 description: “A truck” In your code (or the script/console which should be your new best friend while learning rails) you can see the results from this… person = Person.find(1) # Finds the row in People with id 1. puts “My name is: #{ person.name }” person.things.each() { # using lazy loading it get’s the things for a person to satisfy the relationship. puts “I own: #{ t.description }” } Being this: My name is: John I own: A car I own: A truck I hope this was not a waste of time expanding on WHY Mysql (actually RAILS) didn’t like your column named ID. When you dig deeper in to rails you will learn ways to change the ‘id’ name for your primary to use something else and also how to supress the creating of surrogate keys in your models. - John ---
**Author:** ![mike343](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/58f4c7/32.png) [@mike343](https://www.ruby-forum.com/u/mike343)\ **Post date:** [September 20, 2007, 6:53am UTC](https://www.ruby-forum.com/t/error-after-rake-migrate-db/115040/4 "2007-09-20T06:53:16Z")
> I hope this was not a waste of time expanding on WHY Mysql (actually > RAILS) didn’t like your column named ID. When you dig deeper in to rails > you will learn ways to change the ‘id’ name for your primary to use > something else and also how to supress the creating of surrogate keys in > your models. > > - > > John Definately not a waste of time, very thankful for any help I can get, Michael