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Database systems · Course project

TCGNET

Track exact card printings, manage a collection, and list copies for sale.

  • Lead backend & data engineer
  • Two-person team
  • Django · PostgreSQL
Open project View source

The data model

GameCard + SetExact variant
InventoryOwned & reserved copies
ListingQuantity & asking price
Order lineThe purchased printing
Price historySnapshots over time
A variant joins a card to its set. Inventory, listings, orders, and prices refer to that exact printing.

Purchases update stock in one transaction

Lock
Marketplace services use select_for_update() inside a transaction to coordinate changes to stock.
Validate
Database constraints reject negative quantities, over-reserved inventory, duplicate printings, and buyer-equals-seller orders.
Commit
Stock changes, purchase records, and price history are handled together. The same service boundary covers creating and cancelling listings.

PostgreSQL queries and data imports

Search and collection queries use PostgreSQL trigram matching, partial indexes, aggregation, pagination, and DISTINCT ON. Help controls show the ORM queries behind these features.

The repeatable importer covers 132 default variants from the documented Base and Jungle sets. The course MVP records listings and purchases; payment and shipping are outside its scope.