Rails representer referring to wrong column

I'm currently doing an API which can be used to create productions (movies or series) and relate it to different characters and genres. I'm testing a Genre representer, which should map through associated productions and return a json with all the data, but it is referring to the wrong column. I need it to refer to "production_id" which is in a joined table between genres and productions, but its giving me "productions_id" instead. Here is a link to some screenshots of the controller, params, the representer and the error.