Creating new database views

You can create database views to help hide some of the data structure complexity if there are people who need to access the database directly to extract data/reports for areas that aren’t covered by the default dashboard reports.

These views can be managed using the Django database migrations, to ensure they are added to each implementation/instance of the database. OppiaMobile uses the django-database-view library to assist with setting up and managing views.

Create new views

1. Under reports/models create new db view file

2. Run python manage.py makemigrations

3. Then edit migration file:

   • Add import from dbview.helpers import CreateView

   • Replace migrations.CreateModel with CreateView

   • Check the migration dependencies, you may need to add extra dependencies if you are referencing other models in your view

4. Now run python manage.py migrate

During development and testing you might need to re-run this process several times, eg, as you add columns etc to the output. In which case, each time you edit the definition of you view you’ll need to:

1. Delete the auto-generated (and edited) migration file

2. Drop the view from your database

3. Delete the row in the django_migrations table that references the migration has been applied

Editing existing views

need to be dropped then rebuilt?