VIEW's in sql /oracle

Basic Info of VIEWè

·         A view is a virtual table.

·         It is based on the result-set of an SQL statement.

·         A view contains rows and columns, just like a  table.

·         View’s are created from table or another view.

·         The fields in a view are fields from one or more l tables in the database.

·         You can add SQL functions, WHERE, and JOIN statements to a view.

Difference Between TABLE and VIEWè

·         A table has a set of definition, and it physically stores the data.

·         A view also has a set of definitions, which is build from  table or other view,  

and it does not physically store the data.

SYNTAX->

CREATE or replace VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition

EXAMPLE->

CREATE or replace VIEW  test1_v

AS

Select empno , ename ,salary

From emp

Where salary>5000;

- The above example create a view(test1_v) from table (emp).

-  Like table you can select view using

  “Select * from view_name”

Ex- select * from test1_v;

Result=>

EMPNO          ENAME          SALARY

1                      AMOL             15000

2                      ROHIT             10000

3                      VEENA           12000