I am trying to make django interact with the cassandra database. I was going through the forums and found this
Can this interact with cassandra in django? and are there any libraries that can interact with cassandra in django?
In order to use cassandra (or any other NoSql db) with django you need to have a backend which can support it. Luckily for you though, you're not the first to come up with the idea/need.
Take a look at these resources:
Django NoSql Support
django_cassandra_backend
django-nonrel
nosql-to-people
making django and nosql play nice
I haven't tried any on my own so can't say if anything is stable enough or gives an answer out of the box, but it should send you in the right direction.
Hope this helps.
The best Python client is https://github.com/pycassa/pycassa. You can easily use this from django; https://github.com/twissandra/twissandra is one example.
In my opinion the best way to use Cassandra with Django is cqlengine. It provides beautiful, django-like ORM and is really easy to use. The project seems active, last commit is from few days ago.
You can use it as is or with simple custom django database wrapper django-cassandra-engine.
Related
I am new to cloudantdb and django. Is there any way to integrate cloudantdb with danjgo framework. Is it possible to connect cloudant with django?
As you may be aware, Cloudant is built on Apache CouchDB, so if you can't find references for Cloudant, it's usually worth also searching for CouchDB. I don't really use Django, but a quick search throws up the following references:
http://leok.me/2013/05/02/what-you-need-to-know-couchdb-django/
https://lethain.com/an-introduction-to-using-couchdb-with-django/
http://eflorenzano.com/blog/2008/11/10/using-couchdb-django/
https://djangopackages.org/grids/g/couchdb/
Most if not all solutions on the web are very outdated.
The solution used by IBM in a capstone project on Coursera was:
Use SQLite backend in your Django app
Create Cloud Functions for communicating with Cloudant
Create REST API definitions in your Django app that utilize the Cloud Functions to communicate with Cloudant
I don't know if it's the best solution, but it works. I do feel like SQLite is redundant at this point but without it, I couldn't get the app to work.
In my django application I have essentially joins ("__"). If I were to use Google App Engine, how would my app work in this instance? From what I've read, Bigtable doesn't allow this. Any advice on how to work with this?
Simple answer: it wouldn't.
You would presumably be using django-nonrel in any case. An extension to that, django-dbindexer, provides some support for emulating certain joins. But it's far from comprehensive. You generally need to architect your application in a different way to use the GAE datastore.
According to this question:
Django on Google App Engine
The easiest way to get started with GAE/Django is with the Django non-rel bundle. However now that the latest Python/GAE SDK includes a build of Django, do we still need this?
What's the best-practice for getting started wth Django on GAE right now?
Thanks
Update: It seems that Web app2 is the easiest choice for new projects.
This guest article suggests that
"App Engine does come with some Django support, but this is mainly
only the templating and views."
non-rel is still seemingly your best bet. Although I'd caution you that further development and/or maintenance may not happen according to their blog.
Normal Django's models doesn't have a backend supporting GAE's datastore. Hence you can't use Django models, and hence, Django's model forms. What you'd have to do use use models derived from GAE's python db.Model(). Instead of using Django's ModelForm class for forms, you would use google.appengine.ext.db.djangoforms. Note, that's specifically for ModelForms, other forms work fine since they're not tied to the database.
I can think of two good reasons to use Django-nonrel:
1a) you have a existing project on Django. Using Django-nonrel would be the laziest way to go. Rewriting models to GAE's models isn't too hard, but it could be a small pain, especially if
1b) you use a lot of existing Django components, and you'd have to go through all of them to update the models and forms.
2) You want to hedge your bets against GAE. Using Django-nonrel will allow you to switch over to MongoDB with very little effort, since Django-nonrel has a functioning MongoDB backend. The current Django-nonrel maintainers seem to be more interested in MongoDB.
Having worked with Django-nonrel, I've so far run into some reasons why it may be a bad choice:
1) No support for ancestor queries. There's an outstanding pull request for this though. It won't be compatible with any other DB backend though.
2) ndb is coming out, and seems like it'll have a few more benefits, that likely won't see support on Django-nonrel.
If you do use GAE's native db API, the main benefit from Django would be the form validation. Otherwise, webapp2+jinja2+gae db.Models() would provide similar functionality to Django.
i'm developing a web site hosted on AppEngine and wanted to use Django for some tasks. I've read these two answers:
Django on Google App Engine
Django and App Engine
But those are pretty old, and my question is a little more specific. I've taken a look at django-nonrel and seems good, but i've not used it and cant affirm anything.
So, the question is. Can I use the Admin site and the forms from Django with this package? If not, do you know any other patch that allow me to use them?
Thank you very much!
If you use django-nonrel, then you can use the Django admin site but it will be limited to the types of queries you can do on app engine. I personally found it easier to code my own simple admin interfaces that to type to make things work in Django Admin.
Regarding forms, regular Django Forms and ModelForms work quite well.
Yes, you can (both Admin and forms).
(definitely) :)
I installed djangoappengine 3 months ago and work on it daily under Eclipse (Windows).
If you have some expericence with Django it should be easy, I faced much more problems with Eclipse integration, but nothing unfeseable (even for a newbie - as I'm still).
You just have to start from here:
http://www.allbuttonspressed.com/projects/djangoappengine#installation
Be careful anyway: there are some limitations due to the Datastore capabilities.
A lot of work has been done to circumvent them (dbindexer, specifics decorators...) and if you're planning to develop an app from scratch you will find your way (keeping " noSQL " in mind) but if you plan to migrate a plain vanilla SQL app, it may cause you some pain...
Last point: instances handling Django and all its libraries may be long to start with App Engine ; an issue to consider:
http://code.google.com/p/googleappengine/issues/detail?id=1695
Hope it helps.
Florent
How much of a pain is it to run a Django App on App Engine? Also, does the Datastore work as-is with Django?
I spent some time trying to answer the same question... it seems to me that the most difficult thing to transfer to GAE are django's models... in the sense that they require various modifications and rethinking, mainly because GAE's backend is not a standard relational DB, but google's BigTable. I found a nice intro to this here:
http://www.youtube.com/watch?v=rRCx9e38yr8
Anyways, it's worth downloading one of those 'patches' and have a go with it!
For me the best solution is the 'app-engine-patch'. I downloaded the sample project and it worked straightaway! (Mind that you need to have GAE's SDK installed separately) A killer-feature for me is the fact that the django-admin and many other classic django functionalities have been ported too!!!
http://code.google.com/p/app-engine-patch/
The documentation is still quite minimal in my opinion, but it's good enough to get you going. It'll help you to skim though the official GAE docs though!
Just Yesterday (depending on your time zone), Google released a new SDK for Python on Appengine that supports django 1.0 out of the box.
You need to use django-nonrel (source).
You will still find loads of issues:
Many2Many relations not supported
Fake joins increase number of queries
App Engine doesn't allow any python lib with socket or C dependencies (sentry, lxml...)
You can try to get early access to CloudSQL.
Otherwise you are not constraint to use App Engine, you can think about using:
Heroku
Gondor
Cheaper and more control with support requirement files like pip.
31.01.2012, Google released App Engine 1.6.2 that supports Django out-of-the box.
App Engine includes version 0.96 of Django out-of-the-box, but it is quite crippled.
App Engine Helper and app-engine-patch supposedly fix this problem to some degree, but I haven't tried either myself.
http://code.google.com/appengine/articles/appengine_helper_for_django.html
http://code.google.com/appengine/articles/app-engine-patch.html
The amount of pain depends on how much existing code you want to reuse. Unfortunately because of the Datastore does not support SQL, you often cannot just take any django-pluggable app and use it on your GAE project.
App-engine-patch http://code.google.com/p/app-engine-patch/ looks to be ahead of the other django helpers in bringing the standard applications (Sites, ContentTypes, Flatpages) over to GAE. I have used app-engine-patch on several gae projects, and once you understand how to port a django-sql model to a django-gae model and converting sql to datastore queries things can be done very quickly - but there is always a learning curve.
appengine-helper tries to bridge the Datastore gap by providing a model so you don't have to change your model superclasses, but I've found that you end up having to change ManyToMany relationships and any sql anyway, so the advantage ends up being minimal. ae-patch has a roadmap to try to provide an ae-datastore backend, but it probably won't happen for a while.
Google has now launched their Cloud SQL storage. That is actually MySQL 5.5 in the cloud. IMO that's a very nice way to migrate your Django app into the cloud. They have a free trial up to June 1, 2013.
If you need some tips how to set up your Django project for Appengine and Cloud SQL I've written a tutorial for that.