#107 Migrations in Rails 2.1

最新推荐文章于 2025-07-22 11:34:24 发布

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在Rails2.1中，迁移文件使用时间戳作为版本号。本篇介绍此变更，并展示了如何通过更改表来更新字段类型及名称。

Migrations now have a timestamp as their version number in Rails 2.1. In this episode I will explain this change as well as show you some other cool additions.

# in a migration file
def self.up
  change_table :products do |t|
    t.rename :released_on, :released_at
    t.change :description, :text, :limit => nil, :null => true
    t.remove :price
    t.integer :stock_quantity
  end
end

def self.down
  change_table :products do |t|
    t.rename :released_at, :released_on
    t.change :description, :string, :null => false
    t.decimal :price, :precision => 10, :scale => 2
    t.remove :stock_quantity
  end
end