使用add_reference时指定自定义索引名称

Question

我有以下迁移

class LinkDoctorsAndSpecializations < ActiveRecord::Migration
  def up
    add_reference :doctors, :doctor_specialization, polymorphic: true, index: true
  end

  def down
    remove_reference :doctors, :doctor_specialization, polymorphic: true
  end
end

当我跑,rake db:migrate我得到错误

Index name 'index_doctors_on_doctor_specialization_type_and_doctor_specialization_id' on table 'doctors' is too long; the limit is 63 characters

那么如何在使用add_reference时指定索引名称,就像我们指定的方式一样 add_index :table, :column, :name => 'index name'

Answer 1

正如我评论的那样,做:

add_index :table, :column, name: 'index name' 

这是文档.或者,你可以试试这个:

class LinkDoctorsAndSpecializations < ActiveRecord::Migration
  def change
    add_reference :doctors, :doctor_specialization, polymorphic: true, index: { name: 'index name' }
  end
end

Answer 2

这实际上会起作用：

add_index :table, :column, name: 'index name'

查看更多示例。