Did you know that the possibilities to make a full QGIS back end solution for quality assurance and archiving in PostgreSQL are immense? SQL has it’s well known limitations, but with a little bit creativity you can make quite nice solutions just using triggers and rules. In this post I’ll explain what we did lately based on a project with a customer. He needed to assure the consistency of data but still give his employees the possibility of a fast feeding of the data collected on the field to the database. Another request was to keep every status of the data with the information about the changes (archiving). It’s always the question, where to put the logical part of the solution. QGIS is quite powerful with constraints, but the undeniable advantage of a back end solution is, that you can use any front end - no matter what configuration you have on QGIS or what Feature Manipulation Engine (FME) you use - without influencing the guarantee of data validity.
This is a companion discussion topic for the original entry at https://qfield.org/blog/2018/01/08/postgresql-back-end-solution-for-quality-assurance-and-data-archive/