4h 16m 19s logged

Creating Django Models, Admin Page & Connecting Frontend Pages to Database

Hours: 4.5

Objective

Create Django Models for backend foundation of TradeSims and connect the Login and Register pages to the backend database.

Wrote a markdown file first listing out all the models, fields, and relationships before touching code
Translated that into models.py — ended up with 5 models: Portfolio, Stock, Holding, Transaction, Wishlist
- Portfolio: one-to-one with User, starts everyone off with a $100k balance
- Stock: symbol, price, exchange, etc.
- Holding: links Portfolio + Stock, added a save() override so avg_buy_price calculates itself and the holding deletes itself if quantity hits 0
- Transaction: logs every buy/sell with balance before/after so there’s a proper trade history
- Wishlist: User + Stock, made sure someone can’t wishlist the same stock twice
Used PROTECT on the Stock foreign keys so a stock can’t get deleted while it’s still tied to trades/holdings, but CASCADE on the Portfolio ones since those don’t make sense without the parent
Ran migrations, tested everything through the shell and admin
Set up admin.py for all models + created a superuser
Defined GET and POST conditions for login and register views
Added a component to cleanly display any client-side errors(such as password mismatch)
Checked for multiple edge cases such as:
- Duplicating usernames
- Password mismatch
- Incorrect username or password
- Duplicating email id
Created a simple logout form

on_delete matters more than I thought — CASCADE vs PROTECT changes a lot depending on whether the child record even makes sense without the parent
Doing calculations (like avg_buy_price) inside save() keeps that logic in one place instead of copy-pasting it into views later
Constraints like UniqueConstraint/CheckConstraint let the database stop bad data itself instead of relying only on form validation
GET and POST methods
Login required decorators
Fetching data from HTML forms
Django USER authentication using authenticate

Migration broke when I swapped a CharField (was just storing the stock symbol as text) for a proper ForeignKey to Stock. Django had no way to map the existing text values to actual Stock rows, so it errored out
- Fixed by wiping the db and remigrating since there was no real data yet — if this happens again later with actual data I’ll need a proper data migration instead of just nuking it
Multiple spelling mismatches across files meant that i had to carefully check and re iterate multiple files over and over again
Forgot my superuser username 🤪 which lead me to use shell to retireve it

Fully working relational database — 5 models, all linked up properly with constraints
Django Admin page working for all models
Superuser set up
Functional Login and Register Pages tied to database
Pop up Errors on client side
Both frontend and backend authentication
Simple logout functionality

AI was used as a reviewer and technical mentor to validate database design decisions, strengthen Django concepts, and help debug migration issues.
AI was used as a syntax-reviewer (and in this case, a spelling checker), allowing me to focus on implementing logic in the functions.
All implementation and code integration were completed by me.

Research for the most suitable API key given my current website scope
Implement its API through a HTML form to fetch JSON data
- Parse the data and wire it up to backend
- Create a dashboard with all the user’s data
Implement OAuth Buttons