我正在尝试从网站http://oreilly.com/ruby/archive/rails-revisited.html实现一个 rails Recipe 应用程序。他们给出了一个很好的例子来强调 Rails 对敏捷开发的重要性。本文中的示例是在低于 1.x 的 Rails 版本中实现的。
我正在尝试在 2.0.2 版中实现相同的功能。他们似乎已经使用 MySql 4.1 数据库实现了它。我目前在 Ubuntu 10.04 平台上使用 mysql-client 5.1。当我尝试使用 rake db:migrate 时，我遇到了某些错误。
即使在手动创建数据库表时，我最初也遇到了错误。似乎某些属性的创建数据库表的语法已更改。例如，帖子中创建食谱表的命令对我不起作用
create table recipes (
id int not null auto_increment,
category_id int not null,
title varchar(100) not null default '',
description varchar(255) null,
date date null,
instructions text null,
constraint fk_recipes_categories foreign key (category_id) references categories(id),
primary key(id)
) engine=InnoDB;
直到我改变了语法中的一些东西以适应 5.1 版。对我有用的命令是：
create table recipes ( id int not null auto_increment, category_id int not null, title varchar(100) not null default '', description varchar(255) null, date date null, instructions text null, primary key (id), constraint fk_recipes_categories foreign key (category_id) references categories(id)) engine=InnoDB;
现在回到我的问题。我实际上是在尝试进行某种逆向工程，以了解脚手架的工作原理。最初我想了解它的重要性，所以我尝试手动操作..
然后我尝试使用脚手架命令做事，我目前被 rake db:migrate 困住了。我知道它可能看起来有点过多的参考和一个太大的问题，但我想你需要检查一下，这样你就可以告诉我我需要合并哪些更改才能使用创建我的表耙分贝：迁移
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$ script/generate scaffold category id:integer name:string
/usr/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/rails_generator/lookup.rb:207:Warning: Gem::SourceIndex#search support for Regexp patterns is deprecated, use #find_name
exists app/models/
exists app/controllers/
exists app/helpers/
create app/views/categories
exists app/views/layouts/
exists test/functional/
exists test/unit/
create app/views/categories/index.html.erb
create app/views/categories/show.html.erb
create app/views/categories/new.html.erb
create app/views/categories/edit.html.erb
create app/views/layouts/categories.html.erb
create public/stylesheets/scaffold.css
dependency model
/usr/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/rails_generator/lookup.rb:207:Warning: Gem::SourceIndex#search support for Regexp patterns is deprecated, use #find_name
exists app/models/
exists test/unit/
exists test/fixtures/
create app/models/category.rb
create test/unit/category_test.rb
create test/fixtures/categories.yml
create db/migrate
create db/migrate/001_create_categories.rb
create app/controllers/categories_controller.rb
create test/functional/categories_controller_test.rb
create app/helpers/categories_helper.rb
route map.resources :categories
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$ script/generate scaffold recipe id:integer category_id:integer title:string description:text date:date instructions:text
/usr/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/rails_generator/lookup.rb:207:Warning: Gem::SourceIndex#search support for Regexp patterns is deprecated, use #find_name
exists app/models/
exists app/controllers/
exists app/helpers/
create app/views/recipes
exists app/views/layouts/
exists test/functional/
exists test/unit/
create app/views/recipes/index.html.erb
create app/views/recipes/show.html.erb
create app/views/recipes/new.html.erb
create app/views/recipes/edit.html.erb
create app/views/layouts/recipes.html.erb
identical public/stylesheets/scaffold.css
dependency model
/usr/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/rails_generator/lookup.rb:207:Warning: Gem::SourceIndex#search support for Regexp patterns is deprecated, use #find_name
exists app/models/
exists test/unit/
exists test/fixtures/
create app/models/recipe.rb
create test/unit/recipe_test.rb
create test/fixtures/recipes.yml
exists db/migrate
create db/migrate/002_create_recipes.rb
create app/controllers/recipes_controller.rb
create test/functional/recipes_controller_test.rb
create app/helpers/recipes_helper.rb
route map.resources :recipes
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$ rake db:create
(in /home/mohnish/railsprg/2011/Jan11/12jan11_recipes/cookbook2)
"db/development.sqlite3 already exists"
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$ rake db:create
(in /home/mohnish/railsprg/2011/Jan11/12jan11_recipes/cookbook2)
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$ rake db:migrate
(in /home/mohnish/railsprg/2011/Jan11/12jan11_recipes/cookbook2)
== 1 CreateCategories: migrating ==============================================
-- create_table(:categories)
rake aborted!
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), `name` varchar(255) DEFAULT NULL, `created_at` datetime DEFAULT NULL, `upd' at line 1: CREATE TABLE `categories` (`id` int(11) DEFAULT NULL auto_increment PRIMARY KEY(11), `name` varchar(255) DEFAULT NULL, `created_at` datetime DEFAULT NULL, `updated_at` datetime DEFAULT NULL) ENGINE=InnoDB
(See full trace by running task with --trace)
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$ rake db:migrate --trace
(in /home/mohnish/railsprg/2011/Jan11/12jan11_recipes/cookbook2)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:migrate
== 1 CreateCategories: migrating ==============================================
-- create_table(:categories)
rake aborted!
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), `name` varchar(255) DEFAULT NULL, `created_at` datetime DEFAULT NULL, `upd' at line 1: CREATE TABLE `categories` (`id` int(11) DEFAULT NULL auto_increment PRIMARY KEY(11), `name` varchar(255) DEFAULT NULL, `created_at` datetime DEFAULT NULL, `updated_at` datetime DEFAULT NULL) ENGINE=InnoDB
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract_adapter.rb:150:in `log'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/mysql_adapter.rb:281:in `execute'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/schema_statements.rb:104:in `create_table'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/mysql_adapter.rb:416:in `create_table'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:285:in `send'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:285:in `method_missing'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:265:in `say_with_time'
/usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:265:in `say_with_time'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:281:in `method_missing'
./db/migrate//001_create_categories.rb:3:in `up_without_benchmarks'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:219:in `send'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:219:in `migrate'
/usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:219:in `migrate'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:348:in `migrate'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:339:in `each'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:339:in `migrate'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:307:in `up'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/migration.rb:298:in `migrate'
/usr/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/tasks/databases.rake:85
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain'
/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31
/usr/bin/rake:19:in `load'
/usr/bin/rake:19
mohnish@pc146724-desktop:~/railsprg/2011/Jan11/12jan11_recipes/cookbook2$
db/migrate/001_create_categories.rb & db/migrate/002_create_recipes.rb 看起来像这样：
class CreateCategories < ActiveRecord::Migration
def self.up
create_table :categories do |t|
t.integer :id
t.string :name
t.timestamps
end
end
def self.down
drop_table :categories
end
end
class CreateRecipes < ActiveRecord::Migration
def self.up
create_table :recipes do |t|
t.integer :id
t.integer :category_id
t.string :title
t.text :description
t.date :date
t.text :instructions
t.timestamps
end
end
def self.down
drop_table :recipes
end
end
谢谢你的帮助。。