Error: PG::UndefinedColumn. Custom field not creating column

Support
1

Do topic custom fields add a column to the topics model? I am getting an error saying no, and I’m trying to figure out what to do about it.

I have created a topic custom field in development, following here. Let’s call it fun_level. The custom field seems to be successfully created in development, bc if I do an ajax call to get back a topic I have created after adding the custom field–like ajax("/t/112.json")–it works: the topic data comes back showing the field fun_level with the value I entered.

But now I need to find a way to programmatically retrieve all topics with a certain value for the custom field (eg, get a list of all topics where fun_level = ‘super-duper-fun’).

I’ve considered doing an ajax("/search") for that, but I haven’t gotten it to work yet.

Another method I thought of was to use classic rails: create a controller, and when I go to a certain path (/fun_levels/:fun_level), call the following show method:

  def show 
   respond_to do |format|
      format.json { render json: Topic.where(fun_level: 'super-duper-fun') }
    end
  end

Then, I call ajax("/fun_levels/super-duper-fun.json")…

This controller show method/ajax call strategy works if I am finding topics based on an id, title, etc. But when I use the above code-Topic.where(fun_level: 'super-duper-fun)–it sends an internal server error. And the logs say:

ActiveRecord::StatementInvalid (PG::UndefinedColumn: ERROR: column topics.fun_level does not exist LINE 1: ... "topics" WHERE "topics"."deleted_at" IS NULL AND "topics"."...

Is there a way to get back topics based on a custom field using a controller method, like I’ve provided above? (like my: { render json: Topic.where(fun_level: 'super-duper-fun') })

2

There is a TopicCustomField model. You want that. Maybe have a look at Topic List Previews or some other plugin that mucks with topics. Or maybe see HasCustomFields somewhere in discourse core.

3

Thanks–I was starting to figure something like that must be going on. So perhaps I’d need to do a join with that model (really having to dust off my rails here). I’ve tried something like this:

Topic.joins(:topic_custom_field).where(fun_level: 'super-duper-fun') }

but I get the error: ActiveRecord::ConfigurationError (Can't join 'Topic' to association named 'topic_custom_field'; perhaps you misspelled it?)

Any ideas on the right syntax?

4

I can’t find a TopicCustomField this instant (but I told you where to look! :wink)

Here’s this:

[4] pry(main)> CategoryCustomField.last
=> #<CategoryCustomField:0x000055be74a00bd0
 id: 2,
 category_id: 8,
 name: "enable_accepted_answers",
 value: "true",
 created_at: Mon, 26 Apr 2021 15:45:07.862617000 UTC +00:00,
 updated_at: Mon, 26 Apr 2021 15:45:07.862617000 UTC +00:00>

So something like

tcf=TopicCustomField.where(name: 'fun_level', value: 'super-duper-fun')

Then you can get the topic_id and such from tcf (it’s an array of all matches). If you know the topic_id you could do a TopicCustomField.find_by(<all three things to make it unique>).

5

Cool. Thanks for the info. I’ll experiment with it.

1 Like