Rails: Search method breaks PostgreSQL, alternatives?

I have the following method in my app:

def self.tagged_with( string )
  array = string.split(',').map{ |s| s.lstrip }
  joins(:tags).where('tags.name' => array ).group('photos.id')
end

This is searching photos, which have many tags through taggings.

This method takes a comma separated list of tags and returns any photos that have associated tags with the given names.

The problem is, it breaks PostgreSQL with the following error message:

ActionView::Template::Error (PGError: ERROR:  column "photos.custom_title" must appear in the GROUP BY clause or be used in an aggregate function
: SELECT  "photos".* FROM "photos" INNER JOIN "taggings" ON "photos"."id" = "taggings"."phot开发者_JAVA技巧o_id" INNER JOIN "tags" ON "tags"."id" = "taggings"."tag_id" WHERE "tags"."name" IN ('village') AND ("photos".collection_id = 1) GROUP BY photos.id LIMIT 20 OFFSET 0):

In another somewhat similar question an answerer suggested that whenever using .group() it was necessary to include all columns in the table. This seems insane to me -- what the heck is the point of .group if you can only use it by typing up all the fields in your model. That's brittle, and just a bad idea overall.

Can anyone suggest an alternative way to make this method work with PostgreSQL?

Take a look at this article.

One of the suggestions ("Option 2") is to add select("distinct photos.*") before your join. I've never done this but it seems worth a try; certainly better than putting every selected field into an aggregate function.