再次提交一回
创建模型
Rails 提供了一个生成器用来创建模型
代码语言：javascript复制[root@h202 blog]# bin/rails generate model Article title:string text:text
Running via Spring preloader in process 13216
invoke active_record
create db/migrate/20160422140912_create_articles.rb
create app/models/article.rb
invoke test_unit
create test/models/article_test.rb
create test/fixtures/articles.yml
[root@h202 blog]#生成的两个文件中包含了这个 model 的结构
代码语言：javascript复制[root@h202 blog]# cat db/migrate/20160422140912_create_articles.rb
class CreateArticles < ActiveRecord::Migration
def change
create_table :articles do |t|
t.string :title
t.text :text
t.timestamps null: false
end
end
end
[root@h202 blog]# cat app/models/article.rb
class Article < ActiveRecord::Base
end
[root@h202 blog]#可知这个新生成的 model 继承自 ActiveRecord
进行迁移
迁移就是将前面定义的model ，落实到数据库中形成表结构
代码语言：javascript复制[root@h202 blog]# bin/rake db:migrate
Running via Spring preloader in process 13248
== 20160422140912 CreateArticles: migrating ===================================
-- create_table(:articles)
-> 0.0131s
== 20160422140912 CreateArticles: migrated (0.0132s) ==========================
[root@h202 blog]#那到底将数据结构定义到了哪里呢
代码语言：javascript复制[root@h202 blog]# cat config/database.yml
# SQLite version 3.x
# gem install sqlite3
#
# Ensure the SQLite 3 gem is defined in your Gemfile
# gem 'sqlite3'
#
default: &default
adapter: sqlite3
pool: 5
timeout: 5000
development:
<<: *default
database: db/development.sqlite3
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
<<: *default
database: db/test.sqlite3
production:
<<: *default
database: db/production.sqlite3
[root@h202 blog]# grep -v "^#" config/database.yml
default: &default
adapter: sqlite3
pool: 5
timeout: 5000
development:
<<: *default
database: db/development.sqlite3
test:
<<: *default
database: db/test.sqlite3
production:
<<: *default
database: db/production.sqlite3
[root@h202 blog]# ll db/development.sqlite3
-rw-r--r-- 1 root root 5120 Apr 22 22:19 db/development.sqlite3
[root@h202 blog]#
