Normal Forms in DBMS

There are 5 of there are five different levels of Normal forms let’s see a brief introduction about each normal form

First Normal Form(1NF)

• • A table is said to be in First Normal Form if it is free from multivalued or composite attributes i.e each attribute should be atomic
  • A multivalued attribute is nothing but it contains more than one value in a single cell.

Second Normal Form(2NF)

A table is said to be in Second Normal Form if it satisfies the following two properties

1. It must be in First Normal Form
2. It should be free from all kinds of partial dependencies.

Third Normal Form(3NF)

A table is said to be in Third Normal Form if it satisfies the following properties

1. 1. If it is in second normal form and
   2. There is no transitive dependency.

BCNF(Boyce Codd Normal Form)

The table is said to be in BCNF if it satisfies the following properties

• • It should be in 3nf
  • For every functional dependency, A-> B, A  must be a superkey i.e in any functional dependency LHS attribute  must be a Superkey.

4NF(Fourth Normal Form)

The table is said to be  in the 4th Normal Form it is it satisfies the following properties

• • It should be in Boyce Codd normal form(BCNF)
  • It is free from multivalued dependency