Should I deploy my web server with Django's default database? - python

I'm a noobie to Django and I'm almost at the stage of deploying a web server.
I was just having some doubts with Django's database. Currently I'm using the default sqlite3 database to store all the user models as well as the info models. I'm thinking of using AWS to deploy my web sever.
So when I get to that stage, should I continue with sqlite or should I switch to AWS's database or something like Firebase. If I continue with sqlite, where and how exactly will the information be stored? And what if I switch to something like PostgreSQL, where will the information be stored and will it be secure/fast (even if I manage to get thousands of users)?
Thanks so much, this question might be really basic but I'm super confused.

sqlite is a flat file database, it uses an exposed file in your project to save your data, this is fine in local environment, but when deploying you need to consider that the server and the database are in the same machine and using the same disk. that means if you accidentally remove the machine -and its disk space- used to serve the application, then the database itself will be deleted with all records.
Plus you will face problems if you tried to scale your servers, that is every server will have his own copy of the database and syncing all those files will be huge headache.
If your data is not that important then you can keep using sqlite, but if you are expecting high traffic and complex db structure, then I would recommend you consider a db engine like Mysql or maybe look up the databases offered by amazon here:
https://aws.amazon.com/products/databases/
For django, you will need to change the adapter when using a different db like mysql, sqlite or anything else.
https://docs.djangoproject.com/en/3.0/ref/databases/

Related

Is the sqlite database (the default django database) good enough?

I am building this ecommerce app with django, and I was thinking if the default database (sqlite) was fine enough? My django app is going to have around 200 different products, and for payments I will use stripe API. I do not expect too much traffic when the app is up, since it's a website only for the country I live in with 6 million inhabitants. So can I settle with the sqlite database?
Although your answer may seem opinion based, the right answer is no anyways. SQLite3 is a lightweight database, which is commonlu used when your project is small and you don't mind to start up a server.
SQLite comes with following advantages and disadvantages (source)
Advantages of SQLite
Small footprint: As its name implies, the SQLite library is very lightweight. Although the space it uses varies depending on the system where it’s installed, it can take up less than 600KiB of space. Additionally, it’s fully self-contained, meaning there aren’t any external dependencies you have to install on your system for SQLite to work.
User-friendly: SQLite is sometimes described as a “zero-configuration” database that’s ready for use out of the box. SQLite doesn’t run as a server process, which means that it never needs to be stopped, started, or restarted and doesn’t come with any configuration files that need to be managed. These features help to streamline the path from installing SQLite to integrating it with an application.
Portable: Unlike other database management systems, which typically store data as a large batch of separate files, an entire SQLite database is stored in a single file. This file can be located anywhere in a directory hierarchy, and can be shared via removable media or file transfer protocol.
Disadvantages of SQLite
Limited concurrency: Although multiple processes can access and query an SQLite database at the same time, only one process can make changes to the database at any given time. This means SQLite supports greater concurrency than most other embedded database management systems, but not as much as client/server RDBMSs like MySQL or PostgreSQL.
No user management: Database systems often come with support for users, or managed connections with predefined access privileges to the database and tables. Because SQLite reads and writes directly to an ordinary disk file, the only applicable access permissions are the typical access permissions of the underlying operating system. This makes SQLite a poor choice for applications that require multiple users with special access permissions.
Security: A database engine that uses a server can, in some instances, provide better protection from bugs in the client application than a serverless database like SQLite. For example, stray pointers in a client cannot corrupt memory on the server. Also, because a server is a single persistent process, a client-server database cancontrol data access with more precision than a serverless database, allowing for more fine-grained locking and better concurrency.
It depends where are you going to host it. Some servers do not accept SQLite3 as database and require something more complicated as PostgreSQL (like Heroku). But if you are hosting by yourself (Rapsberry Pi for instance) then it's going to be fine and simple, if the site is going to have small traffic.

How to use mysql online with a desktop app

Is there any way to convert an app written with kivy, python to use an online mysql database, this is usually straight forward for web apps written in python, how about desktop apps written in platforms like kivy and Tkinter that want to use an online mysql database for data sharing?
For this purpose you need a remote mysql server. A local mysql database will only take changes locally, within your computer, but a remote database, will accept data given to them from any device connected to it. There are paid and non paid websites that provide such hosting. Here are some free ones:
FreeMySQLHosting
RemoteMySQL
FreeSQLdatabase
db4free
What you should be looking for is "remote" mysql databases because some online database wont allow you to write to it.
Take a look at this answer for some explanation

Changing Database in run time and making the changes reflect in Django in run time

I am developing a Cloud based data analysis tool, and I am using Django(1.10) for that.
I have to add columns to the existing tables, create new tables, change data-type of columns(part of data-cleaning activity) at the run time and can't figure out a way to update/reflect those changes, in run time, in the Django model, because those changes will be required in further analysis process.
I have looked into 'inspectdb' and 'syncdb', but all of these options would require taking the portal offline and then making those changes, which I don't want.
Please can you suggest a solution or a work-around of how to achieve this.
Also, is there a way in which I can select what database I want to work from the list of databases on my MySQL server, after running Django.
Django's ORM might not be the right tool for you if you need to change your schema (or db) online - the schema is defined in python modules and loaded once when Django's web server starts.
You can still use Django's templates, forms and other libraries and write your own custom DB access layer that manipulates a DB dynamically using python.

Lazy psql connection with Django

I have a Django app that has several database backends - all connected to different instances of Postgresql database. One of them is not guaranteed to be always online. It even can be offline when application starts up.
Can I somehow configure Django to use lazy connections? I would like to:
Try querying
return "sorry, try again later" if database is offline
or return the results if database is online
Is this possible?
The original confusion is that Django tries to connect to its databases on startup. This is actually not true. Django does not connect to database, until some app tries to access the database.
Since my web application uses auth and site apps, it looks like it tries to connect on startup. But its not tied to startup, its tied to the fact that those app access the database "early".
If one defines second database backend (non-default), then Django will not try connecting to it unless application tries to query it.
So the solution was very trivial - originally I had one database that hosted both auth/site data and also "real" data that I've exposed to users. I wanted to make "real" database connection to be volatile. So I've defined separate psql backend for it and switched default backend to sqlite.
Now when trying to access "real" database through Query, I can easily wrap it with try/except and handle "Sorry, try again later" over to the user.

Use two databases in Django 1.5

I have a Django 1.5 application with a SQLite or MySQL database. At the local server I have an Oracle database which I typically connect to with a connection string
"TNS=TNS-name; UID=user; PWD=pwd;".
How is it possible to print data from the local Oracle database in my Django application? Actually, I want to transfer data from the Oracle database into my main SQLite/MySQL database. I've seen some tutorials how to use an Oracle database as main database source in a Django application, but I want to keep my main database source and just load some specific data from the Oracle database in a specific Django view.
Thank you.
I'm not quite sure if this is what you're looking for, but the Django Docs seem to do a good job explaining it (if I interpreted it correctly). In short, you need to add it to your list of databases in your settings file and create a router. The lookup chain for databases is detailed here.

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