What does ER stand for? An Entity Relationship (ER) diagram is one of the most important tools for database design. It helps you visualize the relationships between different entities and how they interact with each other. Many GUI tools have their own tools to build ER diagrams, e.g. pgAdmin IV, DBeaver, etc. In this blog […]

Years ago Years ago I wrote this post describing how to implement 1-to-1 relationship in PostgreSQL. The trick was simple and obvious: You put a unique constraint on a referenced column and you’re fine. But then one of the readers noticed, that this is the 1-to-(0..1) relationship, not a true 1-to-1. And he was absolutely […]