索引名称太长 - Rails 3

时间:2012-10-01 01:56:06

标签: ruby-on-rails ruby-on-rails-3 sqlite rails-migrations

我正在尝试运行此迁移:

class RemoveClientFromSalesteam < ActiveRecord::Migration
    change_table :sales_teams do |t|
        t.remove :client_id
    end
end

这是我得到的错误:

rake db:migrate
-- change_table(:sales_teams)
rake aborted!
An error has occurred, this and all later migrations canceled:

Index name 'temp_index_altered_sales_teams_on_client_priority_and_personal_priority' on table 'altered_sales_teams' is too long; the limit is 64 characters

Tasks: TOP => db:migrate
(See full trace by running task with --trace)

这就是我schema.rb的样子:

  create_table "sales_teams", :force => true do |t|
    t.string   "name"
    t.integer  "firm_id"
    t.boolean  "client_priority"
    t.boolean  "personal_priority"
    t.datetime "created_at",        :null => false
    t.datetime "updated_at",        :null => false
    t.integer  "client_id"
  end

  add_index "sales_teams", ["client_id"], :name => "index_sales_teams_on_client_id"
  add_index "sales_teams", ["client_priority", "personal_priority"], :name => "index_sales_teams_on_client_priority_and_personal_priority"
  add_index "sales_teams", ["name", "firm_id"], :name => "index_sales_teams_on_name_and_firm_id"

思想?

感谢。

1 个答案:

答案 0 :(得分:5)

删除索引,删除列,然后重新添加索引:

def up
  remove_index :sales_teams, :column => [ :client_priority, :personal_priority ]
  remove_column :sales_teams, :client_id
  add_index :sales_teams, [ :client_priority, :personal_priority ]
end

我猜你正在使用SQLite,大多数数据库支持真正的ALTER TABLE操作来删除列,但SQLite强制你复制表(和索引),删除表,然后将所有内容复制回来; Rails SQLite驱动程序在幕后处理这个问题,但显然不知道标识符长度限制。

如果需要,您还可以使用add_indexremove_index:name选项指定自己的索引名称。