what are VIEWS in SQL ?

[Migueel]

Hi,
I am just started learning SQL from last 5 days.I know how to fetch record using query.I just begin to learn chapter on VIEW.I just want to know that why we don't use SELECT command to extract records directly from the table rather than creating a VIEW ?
Please help me.

[Reegan]

A view is a type of virtual table that consists of columns from one or more tables. It is stored in the database. We can fetch data from this view using simple query.It is used to combine data from two or more table.Once you create a view, you can reference it like any other table in a database.A view is use as a security mechanism. It ensures that users are able to retrieve and modify only the specific data seen by them. Users cannot access the remaining data in the underlying tables.

Syntax of view:

CREATE VIEW view_name
[(column_name[,column_name]….)]
[WITH ENCRYPTION]
AS select_statement [WITH CHECK OPTION]

[opaper]

In SQL, a view is like a virtual table based on result of SQL statement.A view is like normal table that contains rows and columns.The columns in a view are columns from one or more real tables in the database.VIEW is mainly used to secure some data from particular tables.

Syntax for creating VIEW:

CREATE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition


You can update a view by using the following syntax:

SQL CREATE OR REPLACE VIEW Syntax
CREATE OR REPLACE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition

[MindSpace]

A view is type of a virtual table. It does not physically exist in database. VIEW is created by using query by joining one or more tables. VIEW is created to retrieve data from one or more tables.


The syntax for creating a VIEW is as follows :

CREATE VIEW view_name AS
SELECT columns
FROM table
WHERE predicates;

view_name specifies the name of the view
column_name specifies the name of the column to be used in view.
table is name of table from which we have to retrieve data.

For example:

CREATE VIEW [Products Above Average Price] AS
SELECT ProductName,UnitPrice
FROM Products
WHERE UnitPrice>(SELECT AVG(UnitPrice) FROM Products)