Foreign key is a reference in one table that points to the primary key in another table. It's a way to link data across multiple tables in a relational database, kind of like hyperlinks connecting web pages together.
When designing the database schema for my new decentralized social network startup, I realized I needed to add a foreign key to the "posts" table to link each post to the user who wrote it. Too bad I can't just store everything on the blockchain and not worry about all these table relationships!
I was debugging a gnarly issue in our enterprise fintech platform and discovered that a foreign key constraint was causing the data integrity exception. I guess even in the era of NoSQL databases, good old fashioned referential integrity still matters.
This article provides a good overview of foreign keys and how they fit into relational database design:
For a deeper dive into data modeling and how foreign keys factor in, check out this piece:
If you're interested in how foreign keys work in the context of database migrations and schema evolution, give this a read:
Note: the Developer Dictionary is in Beta. Please direct feedback to skye@statsig.com.