Question { HP, 6660 }

In which situation you use Self joins?

Answer

We use Self Join, if we have a table that references itself.


For example, In the Employee Table below MANAGERID column
references EMPLOYEEID column. So the table is said to
referencing itself.This is the right scenario where we can
use Self Join.

Question { HP, 5668 }

Describe about first three Normal forms.

Answer

1)1NF
->it has a primary key.
->Each column is atomic.
2)2NF
->It is in 1NF
-> Every non-key column is fully functinally dependend on
primary key.
3)3NF
->It is in 2NF
->Every non-key column is functinally dependend only on
primary key.
->non-key column cant be dependend on another non-key colum.

Question { Wipro, 7244 }

wat is mean by normalization?......programing defination i
need...(i know basic defination)

Answer

Normalisation is to remove the redundancy.
Splitting into smaller oes without effect any data.