SQL VIEW

In this tutorial, we will learn how to use, create and drop VIEW using SQL.

SQL CREATE VIEW

What is the SQL VIEW?

• A VIEW is a virtual table which consists of rows and column like a table and it does not physically exist.
• A VIEW is created by a SQL statement that joins one or more tables.
• If the data changes in the underlying table, then the same changes are also reflected in the VIEW.

Syntax of CREATE VIEW

CREATE VIEW viewName AS
SELECT column1,column2,...columnN
FROM tableName
WHERE condition;

Example of CREATE VIEW

CREATE VIEW EmpData_view AS
SELECT EmpName,Salary,City,Country
FROM Employee
WHERE Country='India'

For Selecting data using VIEW , a query will be:

SELECT * FROM EmpData_view;

SQL Updating a VIEW

A SQL VIEW can be updated with the CREATE OR REPLACE VIEW statement.

Syntax for CREATE OR REPLACE VIEW

CREATE OR REPLACE VIEW viewName AS
SELECT column1,column2,...columnN
FROM tableName
WHERE condition;

Example of CREATE OR REPLACE VIEW

CREATE OR REPLACE VIEW EmpData_view AS
SELECT EmpName,Salary,City,Country
FROM Employee
WHERE Country='India' AND Salary > 18000;

SQL DROP VIEW

A SQL VIEW can be deleted with the DROP VIEW statement.

Syntax For SQL DROP VIEW

DROP VIEW viewName;

DROP VIEW EmpData_view;