Metadata-Version: 2.1
Name: django-db-views
Version: 0.1.0
Summary: Handle database views. Allow to create migrations for database views. View migrations using django code. They can be reversed. Changes in model view definition are detected automatically. Support almost all options as regular makemigrations command
Home-page: https://github.com/BezBartek/django-db-views
Author: Bartłomiej Nowak and Mariusz Okulanis
Author-email: n.bartek3762@gmail.com
License: MIT
Description: # django-db-views
        
        ### How to install?
          - `pip install django-db-views`
        
        ### How to use?
           - add `django_db_views` to `INSTALLED_APPS`
           - use `makeviewmigrations` command to create migrations for view models
        
        
        ### How to create view in your database?
        
        - To create your view use DBView class, remember to set view definition attribute.
        
        
        
            from django_db_views.db_view import DBView
            
            class Balance(DBView):
        
                virtual_card = models.ForeignKey(
                    VirtualCard, on_delete=models.DO_NOTHING, related_name='virtual_cards'
                )
                total_discount = models.DecimalField(max_digits=12, decimal_places=2)
                total_returns = models.DecimalField(max_digits=12, decimal_places=2)
                balance = models.DecimalField(max_digits=12, decimal_places=2)
                
                view_definition = """
                    SELECT
                        row_number() over () as id,  # Django requires column called id
                        virtual_card.id as virtual_card_id,
                        sum(...) as total_discount,
                    ...
                """
            
                class Meta:
                    managed = False
                    db_table = 'virtual_card_balance'
        
        
        
        - The view definition must be a string or a callable. 
        Callable view definition example:
        
        
        
            view_definition = lambda: str(SomeModel.objects.all().query)
        
        
        
        using callable allow you to write view definition using ORM. 
        
        As of version 0.1.0 you can also define view_definition as
        a dict for multiple engine types. This becomes useful if you 
        use a different engine for local / dev / staging / production.
        If you do not pass in an engine and have a str or callable the
        engine will be defaulted to the default database defined in django.settings
        Example as a dict:
        
             view_definition = {
                  view_definition = {
                "django.db.backends.sqlite3": """
                      SELECT
                          row_number() over () as id,
                          q.id as question_id,
                          count(*) as total_choices
                      FROM question q
                        JOIN choice c on c.question_id = q.id
                      GROUP BY q.id
                    """,
                "django.db.backends.postgresql": """
                    SELECT
                        row_number() over () as id,
                        q.id as question_id,
                        count(*) as total_choices
                    FROM question q
                      JOIN choice c on c.question_id = q.id
                    GROUP BY q.id
                """,
            }
             }
        
        
        ### How view migrations work? 
           - DBView working as regular django model. You can use it in any query. 
           - It's using Django code, view-migrations looks like regular migrations. 
           - It relies on `db_table` names. 
           - `makeviewmigrations` command finds previous migration for view.
              - if there is no such migration then script create a new migration
              - if previous migration exists but no change in `view_definition` is detected nothing is done
              - if previous migration exists, then script will use previous `view_definition` for backward operation, and creates new migration.
              - when run it will check if the current default engine definined in django.settings is the same engine the view was defined with
        
        Tested with live projects based on Django: 1.11.5, 2.2.10
        
Platform: UNKNOWN
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.7
Description-Content-Type: text/markdown
