Database- VIEWS

A view is an "Virtual Table". It is not like a simple table, this is an virtual

 table which contains columns and data from different table ( may be one or more

 tables) . View does not contain any data directly, it is a set of query that are

 applied to one or more tables that is stored within the database as object. After

creating a view from some Table, it just used as a reference of those table and when

executed shows only those data which are already mention in query during the creation

 of View.

 use of view:-

      Views are used as Security Mechanism of Database.

Because it restricts user to view certain column and Rows.

 Views display only those data which are mentioned in the query,

 so its shows only those data which returns by the query that is defined

 at the time of creation of view. So rest data are totally abstract from

the end user.

Along with Security the other advantages of view is Data abstraction.

 Because end user is not aware of all the data in Table

+

select *from student

select *from empsiva

create view samps as select a.id,a.name,b.empno,b.ename from student a,empsiva b

drop view samps

select * from samps

delete from samps possible