I tend to forget this simple solution so this post is mostly for myself.
In the Django ORM, we are using order_by to sort results of the query by one or multiple columns. In my case this is something like:
Some of the queries are executed in the result of the form submission. This form contains also information about the sort order required by the client. For safety reasons, I don’t pass form fields directly to the order_by clause. In most cases I’m using a simple construction like this:
# default value sort_order = ['date', 'amount'] if form_sort_field == 'amount': sort_order = ['amount', 'date'] elif form_soft_field == '-amount': sort_order = ['-amount', 'date'] # and later on [...].order_by(*sort_order)
This way I’m sure that the default sort is set and if the proper sorting option is sent by the form, the order_by receives the adjusted sort parameters.