Databases

Question 1

What is 1st normal form?

Answer 1

All rows must be unique( no duplicate)
Each cell must only contain a single value (no list)
Each value must be non divisible (can’t be divided further

Question 2

2nd normal form

Answer 2

Must be in 1nf
No partial dependency- non prime attributes must be functionally dependent on PK/Composite key, not just one PK if theres multiple
dependent-When one changes, the other changes

Question 3

3rd normal form

Answer 3

Must be in 1nf and 2nf
No transitive dependency- All fields must be determinable by PK/CK

Question 4

Primary key

Answer 4

Unique identifier for a table

Question 5

Composite key

Answer 5

One or more PK’s joined together in order to link multiple tables