SQL CREATE OR REPLACE VIEW Statement

The CREATE OR REPLACE VIEW statement in SQL is used to either create a new view or update an existing one. Views are virtual tables based on the result set of an SQL query. They don't store data themselves; they dynamically generate their data when queried.

CREATE OR REPLACE VIEW: Definition and Usage

This command is helpful for modifying views without having to drop and recreate them. If the view already exists, its definition is replaced with the new one; otherwise, a new view is created. This simplifies view management, especially when you need to adjust the underlying query of a view.

Syntax

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

Example: Updating a View

This example adds the "City" column to an existing view named "Brazil Customers". This assumes that the "Customers" table exists and has the columns mentioned.

CREATE OR REPLACE VIEW [Brazil Customers] AS
SELECT CustomerName, ContactName, City
FROM Customers
WHERE Country = "Brazil";
      

Querying the Updated View

After updating the view, you can query it as usual:

SELECT * FROM [Brazil Customers];
      

CustomerName | ContactName | City
---------------------------------
(Data for Brazilian customers from the Customers table)