08. Normal Forms
07 Normal Forms Updated
How to reach First Normal Form (1NF):
- Atomic values: each cell contains unique and single values
- Be able to add data without altering tables
- Separate different relations into different tables
- Keep relationships between tables together with foreign keys
- Atomic values: each cell contains unique and single values
Second Normal Form (2NF):
- Have reached 1NF
- All columns in the table must rely on the Primary Key
- Third Normal Form (3NF):
- Must be in 2nd Normal Form
No transitive dependencies
- Remember, transitive dependencies you are trying to maintain is that to get from A-> C, you want to avoid going through B.
When to use 3NF:
When you want to update data, we want to be able to do in just 1 place. We want to avoid updating the table in the Customers Detail table (in the example in the lecture slide).