ALTER VIEW

A previously created view can be modified using the ALTER VIEW statement.

Syntax:

ALTER VIEW view_name AS select_statement

Example 1:

ALTER  VIEW example_view_name AS (SELECT companyname, productname FROM orderDetailsObject)

Example 2:

ALTER VIEW sophisticatedExampleView as (
SELECT o.orderdate,
       c.country,
       ca.categoryname,
       p.productname,
       p.categoryid,
       o.customerid,
       c.companyname,
       od.productid,
       sum(od.discount) AS discount,
       sum(od.quantity) AS quantity,
       sum(od.quantity*od.unitprice) AS sales
FROM nw_orderdetails od
INNER JOIN nw_orders o
    ON od.orderid=o.orderid
INNER JOIN nw_customers c
    ON o.customerid=c.customerid
INNER JOIN nw_products p
    ON od.productid=p.productid
INNER JOIN nw_categories ca
    ON p.categoryid=ca.categoryid
GROUP BY  o.orderdate,c.country, o.customerid, c.companyname, od.productid, p.productname, p.categoryid, ca.categoryname
ORDER BY  o.customerid, ca.categoryname,p.productname ASC )