finishing off relationship deletion function

web/app/practice.py

             practice.description = description
             db.session.commit()
             if linked_resources:
-                for linked_resource in request.form.getlist('linked_resources'):
+                for linked_resource in linked_resources:
                     link = Resource.query.get(linked_resource)
-                    if link not in links:
+                    if links and link not in links:
+                        add_linked_resource(practice_id, linked_resource)
+                    elif not links:
                         add_linked_resource(practice_id, linked_resource)
             return redirect(url_for('practice.get_practices'))
 

web/app/resources.py

 
 # function to delete a single relationship
 def delete_relationship(first_resource_id, second_resource_id):
-    relation = Relationship.query.filter_by(first_resource_id=first_resource_id).first()
+    relation = Relationship.query.filter((Relationship.first_resource_id == first_resource_id) & (Relationship.second_resource_id == second_resource_id)).first()
     deletion = Relationship.query.get(relation.id)
     db.session.delete(deletion)
     db.session.commit()

web/app/templates/edit.html

           {% for resource_dropdown in resource_dropdown %}
             {% if resource_dropdown['type'] != 'practice' %}
               {% if links and resource_dropdown in links %}
-                <option value="{{ resource_dropdown['id'] }}" selected>{{ resource_dropdown['name'] }}</option>
+                <option value="" selected>{{ resource_dropdown['name'] }}</option>
               {% else %}
                 <option value="{{ resource_dropdown['id'] }}">{{ resource_dropdown['name'] }}</option>
               {% endif %}