Rails app trying to update a nonexistent column -

this on ruby 1.9.3 , rails 3.2.19. i'm not super experienced rails. today started having issue on our live server, works fine on development server.

whenever try give publication model new tags, error:

activerecord::statementinvalid (pg::undefinedcolumn: error: column "taggings_count" not exist line 1: update "tags" set "taggings_count" = oalesce("taggings_count", 0) + 1 "tags"."id" = 47:     app/controllers/publications_controller.rb:162:in 'block in update'   app/controllers/publications_controller.rb:161:in 'update' 

and line 162 of controller is:

def update     @publication = publication.find(params[:id])     if params[:clear_virtual_performances]       @publication.virtual_performances.each {|vp| vp.destroy}     end      if media_id = params["selected_media"]       pub_ids = @publication.publication_media_ids       publicationmedia.update(@publication.publication_media_ids, [{:selected => false}] * pub_ids.length)       publicationmedia.update(media_id, :selected => true)     end      respond_to |format|       if @publication.update_attributes(params[:publication])  // <-------------------         expire_fragments         flash[:notice] = 'publication updated.'         format.html { redirect_to(:action => 'show') }         format.xml  { head :ok }       else         load_extra_vars_for_edit_form                         category.in_slug(params[:default_category])         format.html { render :action => "edit" }         format.xml  { render :xml => @publication.errors,                              :status => :unprocessable_entity }       end     end   end 

however, column "taggings_count" not exist in tags , don't know why looking update in first place. in fact, table on has columns: id, name, position, category_id, , tag_group_id. here tag model:

class tag < activerecord::base   has_many   :taggings   belongs_to :category   belongs_to :tag_group    attr_accessible :name, :position, :category_id, :tag_group_id end 

if there more information should give please let me know; it's vital fixed possible. need error not happen, if means creating dummy column or something.

i guess have counter_cache attribute defined in tagging, belongs_to :publication, counter_cache: true. that's causing counter automagically increment.

you can either remove counter_cache: true or make migration add column.