When working with databases with Django, it automatically creates 12 default tables in the database.
I understand that I need dango_session for storing the session and probably django_site. But why do I need the others?
In PHP I used to store users in my own custom tables. Shouldn't I do that anymore?
The tables are created because you have django.contrib.auth, django.contrib.sessions, and so on in your INSTALLED_APPS setting. You shouldn't delete the tables if the apps are installed, as Django will expect them to exist.
None of the contrib apps are required to run Django. However, I highly recommend that you use the Django auth and sessions app instead of writing your own. For example, if you use the auth app, you don't need to worry about how to hash passwords, and there are lots of helpful views included to log users in, reset passwords and so on.
Related
I have a django project and want to divide it into multiple databases with the same structure.
Use url to distinguish different databases. When the admin management page logs in, log in to different databases according to different urls.
For example: 127.0.0.1/admin uses the admin database, 127.0.0.1/admin2 uses the admin2 database.
Does django implement this function? What do I need to do, Can you give me some suggestions or ideas? thank you very much
TL;DR
As far as a single django project is considered, there is no default way to achieve multiple database.
Scenario 1
From your very limited explaination I will assume that you want to seperate data of one admin dashboard from the data of second admin dashboard, to achieve data isolation with respect to permissions & other models, this is called multitenancy.
Very briefly: In a Multitenant architecture you can have multiple tenants whose structure is defined by your models.py and you can control all this tenant via a main superadmin, these tenants can have their own admin dashboard where the data stored in them are only specific to their tenant users. In more simpler terms you can have a SaaS app with this method, where you can have multiple organizations and these organizations have their own users with their specific permissions/groups.
Multitenancy can be achieved in django via a Schema seperated database using POSTGRESql and this awesome package that has already done most of the heavy lifting for you. You can achieve seperate logins via url or subdomain. If your tenants have users who part of more than one organisation and you want a single login for all of them then you can use this package that goes along with django-tenants. It provides a public user table with permission modules separate for each tenant.
Scenario 2
From your very limited explaination I will assume that you still want seperate databases for your app, in such case you need to rethink your approach to the problem because it is not something you will fancy after deployment as there is not direct way provided by django. Instead you should look into micro-service architecture.
I am going to develop django rest framework apis using postgres legacy database in which apart from the existing tables no other default django tables should be created. I would like to know without creating any django default tables or doing migrations,
can i able to access records from tables using ORM?
Can i able to access admin page without creating django auth table (i.e superuser)?
If no for both questions, only way to connect to db is using any db adapter like psycopg2?
can i able to access records from tables using ORM?
If the schema is same in your models and DB tables, then yes.
Can i able to access admin page without creating django auth table
(i.e superuser)?
As far as I can tell, no, you can't get that, unless your existing 'tables' already have that, and you have all the necessary credentials.
For question in #3, I'd use something less constraining like Flask if you have these problems.
I'm a few weeks into Python/Django and encountering an annoying problem. I have some existing databases set up in settings.py, everything looks good, I've even accessed the databases using connections[].cursor()
But the databases (and data) are not making their way into models that I want to use, despite doing the makemigrations and migrate commands. I was able to use py manage.py inspectdb --database-dbname and copied that class information manually into my models.py, but that didn't work either (typing py manage.py inspectdb on its own does not pull up these databases, I was only able to view by that --database extension). So I'm stumped, as it seems I'm doing all the right steps but not able to use these existing databases in Django.
Any other hints and steps I can take are welcome!
(Almost) all the tutorials, examples, and third-party app you'll find on the internet, and most of the Django documentation assume you use one database for your app. That's because it's fairly tricky and unusual to use multiple databases in one app.
But it's not impossible to use multiple databases and the documentation contains instructions on how to do this and what changes you'll need to make to make it work.
IMO, these are the pre-conditions to use multiple databases in one project:
The databases contain explicitly unrelated information, i.e. you won't have SQL relationships between tables in different databases. One database may contain a table with a column that maps to a column in a table in another database, but they aren't explicit (no ForeignKey or ManyToManyField in your models).
You don't need to mix databases in one query: This basically derives from the previous condition. It just means that if you need to get objects from one database that depend on the rows coming from another database, you establish the relationship in python. E.g. fetching as list of names from one database and using that list to filter a queryset on the other database.
For example, if you have an existing database that contains Strava routes (which are regularly updated via some external mechanism) and your app is a broader app that helps users getting to know their neighbourhood where they can recommend locations and things to do, being able to offer a list of routes with a starting point nearby might be something you'd want to show.
Now that you know this, the way to go is described in the doc linked above:
Create a database router so that queries for certain models are automatically routed to the correct database. E.g. Route.objects.filter(start_city=city) would automatically fetch routes from your Strava routes database.
If you need to save information about a route in your app, save it in a model in the default database and use a unique identifier of the route that will map to the strava database. Use separate queries (no relationships) to fetch information about a specific route.
That being said, if the Strava database is not regularly updated via 3rd channels and its purpose is just to pre-populate your default database, then export the data from the Strava database as json and import it into your django db using manage.py loaddata or a migration file, the latter being more flexible as to the structure of the json file.
I am working on a django app. I understood django creates some tables for users, permissions, groups in database. In that database, already another django app is running. so, already it has default tables. Now, I need to create other app in same database. But I think it creates conflict on users,groups,permissions. So, I want to create all tables with some other names.
Updated
I looked at django-table-prefix which doesn't work with 1.8+ .I am using django 1.10
My question is
How to create/migrate django app with different table names for users,groups, permissions or is there any other way?
Sorry for my silly question. Thanks
If you have an existing Django project, which creates the default tables, you can just add a new **app* to the project. The app can be dependent upon those tables or not, depending on the functionality of the app. Here's the section on Django's website that discusses projects versus apps: https://docs.djangoproject.com/en/1.10/intro/tutorial01/#creating-the-polls-app.
Advanced Use: Here's the section on how to write reusable apps. https://docs.djangoproject.com/en/1.10/intro/reusable-apps/
I hope this helps.
I want to use Pinax for a small project , but I am confused because I don't if can extend/change the behavior and functional of the provided applications .
Is there any documentation for extending the behavior of the bundled applications ?
example: in registration application ,I want to add custom fields but I am not able to find proper documentation on how to achieve it..( mainly for those which need db changes )
Thanks !
Yes, you can extend the behaviour of the built-in applications. If you are using the pinax basic setup with user accounts and profiles, you will have to add the extra fields you want in apps/profiles/models.py. For a list of field types, see here: https://docs.djangoproject.com/en/1.3/ref/models/fields/
This will create the necessary db fields for you when you run manage.py syncdb. If you have already sync'd the db, however, you will have to manually add the db columns. If you don't have any data you care about in that table, you can always just drop the table and it will recreate it. Django doesn't modify db tables once they are created, even if you change the model.
You will also have to modify the signup form to include these new fields and point your urls.py to the new signup form you created. Copy the form from the site-packages/pinax directory to your project. Don't modify them directly.
If you haven't already, you should check out the Django tutorial here: https://docs.djangoproject.com/en/1.3/intro/tutorial01/
This will give you a good idea of how Django apps are put together and how the different pieces interact, so you can do a better job customizing Pinax to your liking. Make sure you know what models.py, urls.py, views.py, and the templates are doing.