mongodb/mongoid · error · Mongoid::Errors::AmbiguousRelationship

Ambiguous associations %{candidates} defined on %{klass}.

Error message

Ambiguous associations %{candidates} defined on %{klass}.

What it means

Error "Ambiguous associations %{candidates} defined on %{klass}." thrown in mongodb/mongoid.

Source

Thrown at lib/mongoid/association/embedded/embedded_in.rb:138

        def polymorphic_inverses(other = nil)
          return unless other

          matches = other.relations.values.select do |rel|
            relation_complements.include?(rel.class) &&
              rel.as == name &&
              rel.relation_class_name == inverse_class_name
          end

          matches.map { |m| m.name }
        end

        def determine_inverses(other)
          matches = (other || relation_class).relations.values.select do |rel|
            relation_complements.include?(rel.class) &&
              rel.relation_class_name == inverse_class_name
          end
          raise Errors::AmbiguousRelationship.new(relation_class, @owner_class, name, matches) if matches.size > 1

          matches.collect { |m| m.name } unless matches.blank?
        end
      end
    end
  end
end

View on GitHub (pinned to 0da0e23d71)

When it happens

Trigger: Thrown at lib/mongoid/association/embedded/embedded_in.rb:138 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of mongodb/mongoid@0da0e23d71 (2026-08-23). Data as JSON: /api/errors/5e931ba9b99da687. Report an issue: GitHub.