Ruby on rails Rails:迁移中重命名列失败

我有一个简单的迁移失败：数据库不受影响，迁移后仍然包含旧列名

class RenameTypeToLicenseTypeInLicenses < ActiveRecord::Migration[5.1]
  def change
    rename_column :licenses, :type, :license_type
  end
end

这是rails db:migrate的输出

igrating to RenameTypeToLicenseTypeInLicenses (20210422110849)
   (0.2ms)  BEGIN
== 20210422110849 RenameTypeToLicenseTypeInLicenses: migrating ================
== 20210422110849 RenameTypeToLicenseTypeInLicenses: migrated (0.0000s) =======

  SQL (0.9ms)  INSERT INTO "schema_migrations" ("version") VALUES ($1) RETURNING "version"  [["version", "20210422110849"]]
   (1.4ms)  COMMIT
  ActiveRecord::InternalMetadata Load (0.5ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", "environment"], ["LIMIT", 1]]
   (0.3ms)  BEGIN
   (0.3ms)  COMMIT
   (0.4ms)  SELECT pg_advisory_unlock(2195010657070977375)
   (0.6ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC

如何重命名

类型

列

编辑： 由于表中的数据很少，我尝试了另一种方法：

remove_column :licenses, :type, :string
add_column :licenses, :license_type, :string

它也不起作用。输出为

[NAME COLLISION] `type` is a reserved key in LicenseResource.
   (0.7ms)  SELECT pg_try_advisory_lock(2195010657070977375);
   (1.3ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
Migrating to ChangeTypeToLicenseTypeFromLicenses (20210422122638)
   (0.5ms)  BEGIN
== 20210422122638 ChangeTypeToLicenseTypeFromLicenses: migrating ==============
== 20210422122638 ChangeTypeToLicenseTypeFromLicenses: migrated (0.0000s) =====

  SQL (1.0ms)  INSERT INTO "schema_migrations" ("version") VALUES ($1) RETURNING "version"  [["version", "20210422122638"]]
   (4.6ms)  COMMIT
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", "environment"], ["LIMIT", 1]]
   (0.4ms)  BEGIN
   (0.4ms)  COMMIT
   (0.6ms)  SELECT pg_advisory_unlock(2195010657070977375)
   (0.9ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC

---

我相信这个答案会帮助你：

---

type

是我们不应该使用的保留字之一。检查此处的其他保留字：

是的，我想知道ActiveRecord的迁移代码是否会尽力保持

类型

的完整性，前提是它当前用于单表继承；它忽略了您想要更改它的事实，因为它当前不是。您可以通过在目标模型中添加以下内容来保留类型列

self.heritation\u column=nil

或

self.heritation\u column='some\u other\u type\u name'

。通过这种方式，AR不会将类型列引用到STI（单表继承），谢谢，我知道这一点，但我更愿意更改列名。使用

type

仍然会从我们使用的JSONAPI:：Resources gem中生成警告。您现有的type列是否包含一些数据？是的，其中包含数据（字符串）。根据您最近在文章中的编辑。在运行

remove\u column

迁移时，数据库中是否仍存在

type

列？（在

schema.rb

文件中可见）如果是，运行迁移时终端上是否有任何错误？感谢您的回答。你写的每件事之前都提到过：你的链接指向一个问题，但第一个答案包含的建议与Farhad Ajaz对我问题的评论相同。问题本身就提到了我问题的原因。

[NAME COLLISION] `type` is a reserved key in LicenseResource.
   (0.7ms)  SELECT pg_try_advisory_lock(2195010657070977375);
   (1.3ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
Migrating to ChangeTypeToLicenseTypeFromLicenses (20210422122638)
   (0.5ms)  BEGIN
== 20210422122638 ChangeTypeToLicenseTypeFromLicenses: migrating ==============
== 20210422122638 ChangeTypeToLicenseTypeFromLicenses: migrated (0.0000s) =====

  SQL (1.0ms)  INSERT INTO "schema_migrations" ("version") VALUES ($1) RETURNING "version"  [["version", "20210422122638"]]
   (4.6ms)  COMMIT
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", "environment"], ["LIMIT", 1]]
   (0.4ms)  BEGIN
   (0.4ms)  COMMIT
   (0.6ms)  SELECT pg_advisory_unlock(2195010657070977375)
   (0.9ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC