Boyce codd introduced a number of normaliztions. It is a multi-step process that puts data into tabular form by removing duplicated data from the relation tables.
Two purposes :
1. Eliminating useless data &
2. Make sure data is logically stored.
Normalization rules :
1. First normalization (1 NF)
2. Second normalization (2 NF)
3. Third normalization (3 NF) &
4. Boyce code normal form (BCNF).
=> First normalization (1 NF) :
It is a property of a relation in a relational database.
a) Each set of column must have an unique value.
b) Each table should be organized into rows and
c) Each row should have a primary key.
Lets consider below table :
Now we are going to make this table in 1NF form.
a) In 1NF.
a) Need more than one table.
b) Redundancy is still there.