0
当我使用t.string或t.number时,我无法创建数据库列。Rails中的简单数据库迁移错误
当我做耙分贝:迁移我得到这个
C:\Ruby\joker\chapter3>rake db:migrate
(in C:/Ruby/joker/chapter3)
== CreateComicBooks: migrating ===============================================
-- create_table(:comic_books)
-> 0.0630s
== CreateComicBooks: migrated (0.0640s) ======================================
我用下面的代码
class ComicBook < ActiveRecord::Base
def self.up
create_table :comic_books do |t|
t.string :title
t.string :writer
t.string :artist
t.integer :issue
t.string :publisher
t.timestamps
end
end
def self.down
drop_table :comic_books
end
end
我也试图与
class ComicBook < ActiveRecord::Base
def self.up
create_table :comic_books do |t|
t.column "title", :string
t.column "writer", :string
t.column "artist", :string
t.column "issue", :number
t.column "publisher", :string
t.timestamps
end
end
def self.down
# called when a migration is reversed
drop_table :comic_books
end
end
在我的数据库得到以下输出
mysql> show tables;
+-----------------------------------+
| Tables_in_comic_books_development |
+-----------------------------------+
| comic_books |
| schema_migrations |
+-----------------------------------+
2 rows in set (0.00 sec)
mysql> describe comic_books;
+------------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+----------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| created_at | datetime | YES | | NULL | |
| updated_at | datetime | YES | | NULL | |
+------------+----------+------+-----+---------+----------------+
3 rows in set (0.01 sec)
mysql>
现在,当我试图创造一个新的纪录我得到这个
C:\Ruby\joker\chapter3>ruby script/console
Loading development environment (Rails 2.3.8)
>> mycb = ComicBook.new
=> #<ComicBook id: nil, created_at: nil, updated_at: nil>
>> mycb.title = 'All new'
NoMethodError: undefined method `title=' for #<ComicBook id: nil, created_at: ni
l, updated_at: nil>
from C:/Ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record
/attribute_methods.rb:259:in `method_missing'
from (irb):2
我认为它是一个很小的错误,但我只是不能想出办法来的。
期待您的帮助和支持。
谢谢
您正在将模型中的迁移。这是不正确的。参考tsdbrown的答案来解决你的问题。有人已经在你的其他问题中告诉过你...(http://stackoverflow.com/questions/3777645/error-while-creating-new-object-in-rails)。 – Mischa 2010-09-23 13:19:01