Benefits of Using Views

Design Flexibility: By using a view instead of a query in an application, it is easier to make changes to the underlying table structure.
Improved Security: By using a view to return data from tables instead of a SELECT, you can hide the WHERE clause or other columns to which you do not want the user to have access.
Query Simplification: You can write simple select statements against views, which handle complex queries and joins.

Code Sample:

USE WORLD; CREATE VIEW city_country AS SELECT ci.name AS city_name, co.name AS country_name FROM city ci JOIN country co ON ci.CountryCode = co.Code;

Results by selecting from the city_country view:

CREATE VIEW city_country AS

Create a new VIEW object and give it the name city_country
The AS statement precedes the query that will be assigned to the VIEW

SELECT ci.name AS city_name, co.name AS country_name

Only the columns defined in the SELECT statement will be available to the VIEW
It is a good idea to provide a column alias in the select because the VIEW will not have access to the underlying table structure.

FROM city ci

JOIN country co

ON ci.CountryCode = co.Code;

The JOIN statement of the SELECT.
Once you have created a VIEW, you can run SQL statements using the VIEW as if it were a table.
By creating a VIEW, we can run selects that retrieve data from multiple tables without having to re-code a join.
Notice how the SELECT * retrieves only the rows defined in the SELECT statement used in the VIEW creation.
If you want to drop a VIEW, we can run the DROP VIEW statement
If you want to modify an existing view you can use the statement CREATE OR REPLACE VIEW. That way you do not have to run a DROP VIEW statement and then a CREATE VIEW statement.