View

In Oracle, a View is a virtual table created from the result of a SQL query. It does not store data itself; instead, it stores the SQL statement. Whenever you query the view, Oracle retrieves the latest data from the underlying base table(s).

Syntax

CREATE VIEW view_name AS
SELECT column1, column2, ...
FROM table_name
WHERE condition;

Example

Suppose you have an EMPLOYEES table:

Create a view that shows only IT employees:

CREATE VIEW it_employees AS
SELECT emp_id, name, salary
FROM employees
WHERE dept = 'IT';

Query the view:

SELECT * FROM it_employees;

Output:

Advantages of Views

• Simplifies complex SQL queries.
• Restricts access to selected rows or columns for security.
• Hides the complexity of joins and calculations.
• Always displays the latest data from the base tables.

Other useful commands

Display a view:

SELECT * FROM view_name;

Replace an existing view:

CREATE OR REPLACE VIEW view_name AS
SELECT ...
FROM ...;

Delete a view:

DROP VIEW view_name;