Is there a way to map data from form to insert in to database without explicitly defining each variable?

Question

I have made a really long form with the help of colander alchemy and deform.

This form has 100 or so fields and currently the only way I know to add the data back to the database once form is submitted is to explicitly re-define each variable and then add that to the database but there must be a better way.


#my schema 

class All(colander.MappingSchema):
                setup_schema(None,atr)
                atrschema =atr.__colanderalchemy__
                setup_schema(None,chemicals)
                chemicalsschema =chemicals.__colanderalchemy__
                setup_schema(None,data_aquisition)
                data_aquisitionschema =data_aquisition.__colanderalchemy__
                setup_schema(None,depositor)
                depositorschema =depositor.__colanderalchemy__
                setup_schema(None,dried_film)
                dried_filmschema =dried_film.__colanderalchemy__

form = All()
form = deform.Form(form,buttons=('submit',))

# this is how I get it to work by redefining each field but there must be a better way

if 'submit' in request.POST:

   prism_material = request.params['prism_material']
   angle_of_incidence_degrees = 
   request.params['angle_of_incidence_degrees']
   number_of_reflections = request.params['number_of_reflections']
   prism_size_mm = request.params['prism_size_mm']
   spectrometer_ID = 6

   page = atr (spectrometer_ID=spectrometer_ID,prism_size_mm=prism_size_mm,number_of_reflections=number_of_reflections,angle_of_incidence_degrees=angle_of_incidence_degrees,prism_material=prism_material)

   request.dbsession.add(page)




Would like to somehow just be able to remap all of that 'multi dictionary' that is returned back to the database?

You could use an array of keys, iterate through that, and create a dict from the iteration. — Steve Piercy, Jun 20 '19 at 18:29

Sergey · Accepted Answer · 2019-06-20T21:40:20.983

So, you have a dict (request.params) and want to pass the key-value pars from that dict to a function? Python has a way to do that using **kwargs syntax:

if 'submit' in request.POST:
   page = Page(spectrometer_ID=6,**request.params)   
   request.dbsession.add(page)

(this works also because SQLAlchemy provides a default constructor which assigns the passed values to the mapped columns, no need to define it manually)

Of course, this is a naive approach which will only work for the simplest use-cases - for example, it may allow passing parameters not defined in your schema which may create a security problem; the field names in your schema must match the field names in your SQLAlchemy model; it may not work with lists (i.e. multiple values with the same name which you can access via request.params.get_all(name)).

Is there a way to map data from form to insert in to database without explicitly defining each variable?

1 Answers1