Sql

Normalization

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

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