Question

环境：Rails 3.2.11

添加了paper_trail gem。

请注意，我已经使用过那个宝石而且我从来没有遇到过任何问题，但这次我收到了一个错误，我找不到原因。

在我的模型中：

class User < ActiveRecord::Base
  has_paper_trail :versions => :paper_trail_versions
  ...
end

错误：

  User Exists (0.6ms)  SELECT 1 AS one FROM "users" WHERE ("users"."pseudo" = 'joel' AND "users"."id" != 21) LIMIT 1
PG::Error: ERROR:  relation "versions" does not exist
LINE 5:              WHERE a.attrelid = '"versions"'::regclass
                                        ^
:             SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                     pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
              FROM pg_attribute a LEFT JOIN pg_attrdef d
                ON a.attrelid = d.adrelid AND a.attnum = d.adnum
             WHERE a.attrelid = '"versions"'::regclass
               AND a.attnum > 0 AND NOT a.attisdropped
             ORDER BY a.attnum

   (0.1ms)  ROLLBACK
Completed 500 Internal Server Error in 28ms

ActiveRecord::StatementInvalid (PG::Error: ERROR:  relation "versions" does not exist
LINE 5:              WHERE a.attrelid = '"versions"'::regclass
                                        ^
:             SELECT a.attname, format_type(a.atttypid, a.atttypmod),
                     pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
              FROM pg_attribute a LEFT JOIN pg_attrdef d
                ON a.attrelid = d.adrelid AND a.attnum = d.adnum
             WHERE a.attrelid = '"versions"'::regclass
               AND a.attnum > 0 AND NOT a.attisdropped
             ORDER BY a.attnum
)

有关如何解决此问题的任何线索？

Answer 1

您是否遵循了安装说明：

通过您的Gemfile将PaperTrail安装为gem：

gem'paper_trail'，'〜＆gt; 2'

生成迁移，将版本表添加到数据库中。

bundle exec rails generate paper_trail:install

运行迁移。

bundle exec rake db:migrate

将has_paper_trail添加到要跟踪的模型中。

来自https://github.com/airblade/paper_trail

papertrail“版本”不存在

1 个答案: