我想在我的索引表中添加另一个索引列,但是收到的表索引太长;限制为 64 个字符。顺便说一句,Rails 3 和 MySQL DB。
当前架构如下:
create_table "admin_users_projects", :force => true do |t|
t.integer "admin_user_id"
t.integer "project_id"
end
add_index "admin_users_projects", ["admin_user_id", "project_id"], :name => "index_admin_users_projects_on_admin_user_id_and_project_id"
我正在尝试运行以下迁移来添加索引:
class AddIndexToAdminUsersProjects < ActiveRecord::Migration
def change
add_index :index_admin_users_projects_on_admin_user_id_and_project_id, :admin_users_project_id
end
end
但是在尝试 rake 时得到以下信息(简而言之):
Larrys-MacBook-Pro:scrumtool larrydavid$ rake db:migrate
== AddIndexToAdminUsersProjects: migrating ===================================
-- add_index(:index_admin_users_projects_on_admin_user_id_and_project_id, :admin_users_project_id)
rake aborted!
An error has occurred, all later migrations canceled:
Index name 'index_index_admin_users_projects_on_admin_user_id_and_project_id_on_admin_users_project_id' on table 'index_admin_users_projects_on_admin_user_id_and_project_id' is too long; the limit is 64 characters
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