# Introduction - [Database concepts — Isaac Computer Science](https://isaaccomputerscience.org/topics/databases?examBoard=aqa&stage=a_level) # Normalization "The key, the whole key and nothing but the key" or - Flatten it - Remove partial dependencies - Remove non key dependencies - [Database Normalization 1NF 2NF 3NF - YouTube](https://www.youtube.com/watch?v=SK4H5tTT6-M) - [Database Normalization in SQL with Examples – SQLServerCentral](https://www.sqlservercentral.com/articles/database-normalization-in-sql-with-examples) - [Entity Relationship Diagrams | Mermaid](https://mermaid.js.org/syntax/entityRelationshipDiagram.html) (Click on the Live Editor at the top of the screen to draw your own) # SQL - [SQLZoo](https://sqlzoo.net/wiki/SQL_Tutorial) [[SQL Helpsheet]]