生成许多​​模型来许多铁轨3 [英] Generating a model with many to many in rails 3

问题描述

有没有办法产生具有许多铁轨模型一对多关系predefined？我知道如何在事后将其添加到活动的记录，但它会是不错的它在数据库迁移和活动记录模式马上蝙蝠定义。

Is there a way to generate a rails model with a many to many relationship predefined? I know how to add it to the active record after the fact but it would be nice to have it defined in the db migration and the active record model right off the bat.

推荐答案

请记住，你不想要一个ID为连接表，所以一定要补充：ID =>假| T |

Remember that you do not want an id for the join table, so make sure to add :id => false |t|

create_table assemblies_parts, :id => false do |t|
  t.integer :assembly_id
  t.integer :part_id
end

如果您使用的轨道

rails generate model Assemblies_parts assembly:references part:references

您将有两个指标，但你想要的是

you will have two indexes, but what you want is

# Add table index
add_index :assemblies_parts, [:assembly_id, :part_id], :unique => true

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