Lesson 25 Advanced Level
25 of 30 lessons

Views

Learn how to create and use views to simplify complex queries and provide data abstraction. Views are virtual tables that simplify data access.

What is a View?

A View is a virtual table based on the result of a SQL query. It stores no data itself but provides a way to simplify complex queries and enhance security.

Creating a View

CREATE VIEW employee_info AS
SELECT employee_id, first_name, last_name, salary
FROM employees
WHERE status = 'ACTIVE';

This creates a view named employee_info that shows only active employees.

Querying a View

SELECT * FROM employee_info;

Modifying a View

CREATE OR REPLACE VIEW employee_info AS
SELECT employee_id, first_name, department_id
FROM employees
WHERE status = 'ACTIVE';

Dropping a View

DROP VIEW employee_info;

Benefits of Views

  • Simplify complex queries
  • Enhance security by restricting access to sensitive columns
  • Improve logical data independence

Practice Task