在插件中使用 HasCustomFields

开发
3

非常感谢你，David！

是的，这可能就是问题所在。我想我本该把这条错误信息也包含进来。而且，我可以让迁移在任一字段下都能工作（不过，如果字段名是 pfaffmanager_server_id，索引名称就会超过 63 个字符，所以我必须为索引使用不同的名称）。

让我再试一次。

字段名为 server_id

class CreatePfaffmanagerServerCustomField < ActiveRecord::Migration[6.0]
  def change
    create_table :pfaffmanager_server_custom_fields do |t|
      t.integer :server_id, null: false
      t.string :name, limit: 256, null: false
      t.text :value
      t.timestamps null: false
    end
    add_index :pfaffmanager_server_custom_fields, [:server_id, :name]
  end
end

保存时失败，报错如下：

 Pfaffmanager::ServerCustomField Load (3.8ms)  SELECT "pfaffmanager_server_custom_fields".* FROM "pfaffmanager_server_custom_fields" WHERE "pfaffmanager_server_custom_fields"."server_id" = 1
   (1.4ms)  ROLLBACK
PG::UndefinedColumn: ERROR:  column "pfaffmanager_server_id" of relation "pfaffmanager_server_custom_fields" does not exist
LINE 1: INSERT INTO pfaffmanager_server_custom_fields (pfaffmanager_...
                                                       ^

看来它在查找 pfaffmanager_server_id。现在，让我们改用 pfaffmanager_server_id。

字段名为 pfaffmanager_server_id

这是迁移代码：

class CreatePfaffmanagerServerCustomField < ActiveRecord::Migration[6.0]
  def change
    create_table :pfaffmanager_server_custom_fields do |t|
      t.integer :pfaffmanager_server_id, null: false
      t.string :name, limit: 256, null: false
      t.text :value
      t.timestamps null: false
    end
    add_index :pfaffmanager_server_custom_fields,
      [:pfaffmanager_server_id, :name],
      name: 'index_pfaffmanager_server_custom_fields_on_server_id_and_name'

  end
end

当我尝试访问 s.custom_fields 时发生了以下情况（上面的代码在访问时能返回 nil，但直到我尝试保存自定义字段时才失败）。我在这里调用了 register_custom_field_type：

 pry(main)> s.custom_fields
   (1.1ms)  SELECT "pfaffmanager_server_custom_fields"."name", "pfaffmanager_server_custom_fields"."value" FROM "pfaffmanager_server_custom_fields" WHERE "pfaffmanager_server_custom_fields"."server_id" = 1 ORDER BY id asc
ActiveRecord::StatementInvalid: PG::UndefinedColumn: ERROR:  column pfaffmanager_server_custom_fields.server_id does not exist
LINE 1: ...e" FROM "pfaffmanager_server_custom_fields" WHERE "pfaffmana...
                                                             ^

from /home/pfaffman/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rack-mini-profiler-2.3.0/lib/patches/db/pg.rb:69:in `exec_params'
Caused by PG::UndefinedColumn: ERROR:  column pfaffmanager_server_custom_fields.server_id does not exist
LINE 1: ...e" FROM "pfaffmanager_server_custom_fields" WHERE "pfaffmana...
                                                             ^

现在它又在查找 server_id 了。

看来 custom_fields 想要一种字段名，而 save_custom_fields 却想要另一种。

它并不在意索引名称是什么，对吧？