Last updated on August 23, 2021
https://vertabelo.com/blog/how-to-remember-database-normal-forms/
Normal Forms: A Recap
The key, the whole key, and nothing but the key, so help me Codd.
The key stands for 1NF: all tables must have a (primary) key because all records in the table must be unique.
The whole key stands for 2NF: no functional dependencies on part of the key are allowed.
Nothing but the key (attribute) stands for 3NF: no functional dependencies between non-key attributes are allowed.
Nothing but the key stands for BCNF: only functional dependencies out of candidate keys are allowed.
“2NF/3NF: Every non-key attribute is
dependent on the key, the whole key, and nothing but the key—so help me Codd.”
Example:
The db from…
Database diagram used for some learning (Bikestore)
The rest is here:
https://github.com/spawnmarvel/t-sql
https://www.studytonight.com/dbms/boyce-codd-normal-form.php
Relationships
https://fmhelp.filemaker.com/help/18/fmp/en/index.html#page/FMP_Help%2Frelationships.html%23