SQL VIEWS
Introduction
A view is a virtual table. It is used to summarize data from various tables that helps to generate reports. A view always shows updated data.
1. CREATE VIEW Statement
- SQL VIEW is a virtual table and it contains rows and columns just like real table.
- The fields of views are selected from one or more real tables in the database.
Syntax:
CREATE VIEW view_name AS
SELECT column_name
FROM table name
WHERE [condition];
Example : Query using CREATE VIEW Statement
Consider the following table titled
'Students'.
| Stud_ID | Stud_Name | City | Country |
|---|
| 1 | Mark | London | England |
| 2 | Alex | Paris | France |
| 3 | Bob | Sydney | Australia |
| 4 | Jaya | Delhi | India |
| 5 | Surendra | Baroda | India |
Write a query to create a view of columns such as Stud_ID, Stud_Name, City from the above table 'Students'
CREATE VIEW Stud AS
SELECT Stud_ID, Stud_Name
FROM Students
WHERE Country = 'India';
Result is shown in the following table.
| Stud_ID | Stud_Name |
|---|
| 4 | Jaya |
| 5 | Surendra |
Note : SELECT * FROM students; statement is used to see the created view.
2. SQL DROP VIEW Statement
The SQL DROP VIEW Statement is used to delete or remove the view.
Syntax:
DROP VIEW View_name;
Example : Query using DROP VIEW Statement.
If user needs to delete view titled as
'Students'. The query should be written as:
DROP VIEW Students;
