如何在 Ruby on Rails ActiveRecord 迁移中处理过长的索引名称?

问题描述

我正在尝试添加一个从四个关联表的外键创建的唯一索引:

I am trying to add an unique index that gets created from the foreign keys of four associated tables:

add_index :studies,
  ["user_id", "university_id", "subject_name_id", "subject_type_id"],
  :unique => true

数据库对索引名的限制导致迁移失败.这是错误消息:

The database’s limitation for the index name causes the migration to fail. Here’s the error message:

表 'studies' 上的索引名称 'index_studies_on_user_id_and_university_id_and_subject_name_id_and_subject_type_id' 太长；限制为 64 个字符

我该如何处理?我可以指定不同的索引名称吗?

How can I handle this? Can I specify a different index name?

推荐答案

为 ，例如:

Provide the :name option to add_index, e.g.:

add_index :studies,
  ["user_id", "university_id", "subject_name_id", "subject_type_id"],
  unique: true,
  name: 'my_index'

如果在 :index 选项 rel="noreferrer">references 在 create_table 块中，它采用与 add_index 相同的选项哈希作为其值:

If using the :index option on references in a create_table block, it takes the same options hash as add_index as its value:

t.references :long_name, index: { name: :my_index }

这篇关于如何在 Ruby on Rails ActiveRecord 迁移中处理过长的索引名称?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！