I want to make a website that gives a visualization of football game statistics.
Functionality: The user checks a list of games. Selects game to see details. Can select a particular player. If there is no game he/she is interested in, the user uploads a datafile of the game and adds it to the main list of games.
I have a script that cleans data and gives me DataFrame with columns:
['Shots', 'SCA', 'Touches', 'Pass', 'Carries', 'Press', 'Tackled', 'Interceptions', 'Blocks']
if I do the Django model is it ok if I simply do model with these columns, or do I need to do a proper database with separate tables like:
Is my UML is ok or do I need to fix something?
here is link to my UML https://drawsql.app/xml-team/diagrams/football-game-stats
You don't need to manually create tables and relations in your database, Django can take care of that for you.
It has been explained in detail here
I suggest following these simple steps for building Django Model. I always did by following these steps.
Create Django Application
Add the Posts Model
Update Settings
Make Migrations
Verify Database Schema
Related
I'm a beginner at Django, and as a practice project I would like to create a webpage with a dashboard to track investments in a particular p2p platform. They do not have a nice dashboard (but provide excel file with all data). As I see it, main steps that I need to do in this project are as follow:
Create login so that users would have account where they upload their excel files.
Make it possible to import excel file to a database
Manipulate/calculate data for it to be later used in dashboard
Create dashboard.
Host webpage.
After some struggle I have implemented point no. 2, and will deal with 1 and 5 later. But number 3 is my biggest issue now.
I'm completely unsure what I need to do, and google did not help. I need to calculate data before I can make dashboard from it. Union two of the tables, and then join them together with a third table, creating some additional needed calculated fields. Do I create a view in the database and somehow fetch this data to Django? Or do I need to create some rules so that new table would be created at the time of the import? I think having table instead of a view would have better performance. Or maybe I'm doing it completely wrong, and should take completely different approach for this kind of task? Also, is SQLite a good database for a task (I'm using it, because it was a default in Django)?
I assume for vizualization part I will need to do it with some JavaScript library, such as D3? Which then would use data from step 3.
For part 3 there is 2 way, either do these stuff and save the result in your database or you can do it when you need it using django model features like annotation, aggregation and etc.
Option 1 requires to add a table for you calculation which is Models in django.
Option 2 requires to create a doing the annotations in a view or model managers and then using them in views.
Django docs: Aggregation
Which is the best is depended on how big your data is, how complicated the calculation is and how often you need them.
And for database; SQLite is just a database for development use not the production and surly not with a lot of data and a lot of calculations. The recommended database for django is postgresql which is pretty good at handling millions and even billions of data and doing heavy calculation.
And for vizualization you should handle it on the template side which is basically HTML, CSS and JS.
I am working on my first django-viewflow project, and I have some very basic questions. I have looked at the docs and the cookbook examples.
My question is which fields go into the "normal" django models (models.Model) and which fields go into the Process models? For example, I am building a publishing model, so a document that is uploaded starts in a private state, then goes into a pending state after some processing, and then an editor can update the documents state to publish, and the document is available through the front facing web site. I would assume the state field (private, pending, publish) are part of a process model, but what about the other fields related to the document (author, date, source, topic, etc.)? Do they go into the process model or the models.Model model? Does it matter? What are the considerations in building the models and flows for separation of data between the two types of models?
Another example - why in the Hello World example is the text field in the Process model and not a model.Models model? This field does not seem to have anything to do with the process, but I am probably not understanding how viewflow works.
Thanks!
Mark
That's your choice. Viewflow is the library and has no restriction on data alignment. The only thing that needs to be done is the link between process_pk and the process data. HelloWord is the minimal working sample, that demonstrates a workflow.
You can put everything in the separate mode and provide an FK to in the Process model.
But the state field itself is the antipattern since eventually, you can have several tasks executed in parallel. And even sequential workflow could be constantly changed, new tasks could be added or deleted. You can have only published Boolean or DateTime field in the POST model to filter on that on the front end.
The general rule could be - keep all people workflow decisions in the Process model, and build all data models in a declarative way, keep separated workflow and actual data.
I am trying to learn Django and so far I have been able to create models and be able to inject data into the database using views and have a small web app working nicely.
I have a small confusion regarding how Django works with tables that will need to be populated outside the application.
For example, I should have a table called Products. Now the products change extremely infrequently and moreover there are some products that the database should already be populated with. For example, my product model could be simple as:
class ProductModel(models.Model):
name = models.CharField(max_length=200)
What is the Django-nic way to pre-populate this table with a set of products already?
For Products that should already be populated you could use initial data to prepopulate
If some external software wants to change the product list, well hmm if you need to do it manually you can create a data migration
...or you could create a view that takes a json as input ant populates the Projects table using bulk_create() or a simple create()
...or you can create a custom command that another program can call like python manage.py import_products my_products.json
...or make the external application to insert the products into the same database will be ok too.
I have a project that looks like a simple shopping site that sells different kinds of products. For example, I have 4 models: Brand, Product, Consignment. Consignment is linked to Product, and Product is linked to Brand. To reduce count of queries to databases, I want to save current state of these models(or at least some of them). I want to do it, because I show a sidebar with brands and products. So every time when user opens some page, it will execute the query to database to get those brands and products.
But when admin add some new product or brand, I want to handle database changing and resave it. How to implement it?
Your answer is by using Cache. Cache is a method to store your objects in memory/other app like redis temporarily so that you do not need send queries to database. You can read the full description here.
Or, you can use this third party library that helps you to cache Django ORM Model. Here are the example.
Brand.objects.filter(name='stackoverlow').cache()
After doing an update to the model, you need to clear or invalidate the cache.
invalidate_model(Brand)
I am doing a poc in Django and i was trying to create the admin console module for inserting,updating and deleting records through django admin console through models and it was doing fine
I have 2 questions.
1.I need to have model objects for existing tables which needs to be present in a particular schema.say schema1.table1
Here as of now i was doing poc for public schema.
So can it be done in a fixed defined schema and if yes how.Any reference would be very helpful
2.Also i wanted to update few columns in the table through console and the rest of the columns will be done automatically like currentimestamp and created date etc.Is it possible through default django console and if yes kindly share any reference
Steps for 1
What i have done as of now is created a class in model.py with attributes as author,title,body,timeofpost
Then i used sqlmigrate after makemigrations app to create the table and after migrating have been using the admin console for django to insert and update the records for the table created.But this is for POC only.
Now i need to do the same but for existing tables with whom i can interact and insert or update record for those existing tables through admin console.
Also the tables are getting created in public schema by default.But i am using postgres and the existing tables are present in different schemas and i wanted to insert,update and delete for this existing tables.
I am stuck up here as i dont know how to configure model with existing database schema tables through which we can interact through django console and also for different schemas and not in public schema
Steps for 2:
Also i wanted the user to give input for few columns like suppose in this case time of creation is not required to be given as input by user .Rather it should be taken care when the database is updating or creating
Thanks
In order for Django to "interact" with an existing database you need to create a model for it which can be done automatically as shown here. This assumes that your "external" database isn't going to be changed often because you'll have to keep your models in sync which is tricky - there are other approaches if you need that.
As for working with multiple database schemas - is there a reason you can't put your POC table in the same database as the others? Django supports multiple databases, but it will be harder to setup. See here.
Finally, it sounds like you are interested in setting the Django default field attribute. For an example of current time see here.