How to avoid triggering unique validator on model edition?

Question

I'm using Flask, SQLAlchemy and WTForms. I have a number of properties in my model object which are marked as unique and nullable=False. This works fine when creating a new row in the database but when I try to edit an existing object the validator on WTForms fails with

{'aproperty': [u'Already exists.']}

How can I make this validation pass without having to change my data model?

Update

Following the documentation was of no use to me.

Answer 1

You need to associate the existing record with the form. Otherwise the validator has no way of knowing that you're updating an existing record instead of creating a new one. Something like the following should do the trick:

current_obj = ...
form = MyForm(request.form, obj=current_obj)
form.validate_on_submit():
    form.populate_obj(current_obj)