Page 63 - Modular_V2.0_SQL_Flipbook

Output:
+--------------+-------+----------+----------+-------------+
| Product_name | Price | Quantity | Discount | Total_sales |
+--------------+-------+----------+----------+-------------+
| Laptop | 50000 | 5 | 500 | 250000 |
+--------------+-------+----------+----------+-------------+
| Smartphone | 15000 | 10 | 1000 | 150000 |
+--------------+-------+----------+----------+-------------+
| Headphones | 2500 | 15 | 300 | 37500 |
+--------------+-------+----------+----------+-------------+
| Keyboard | 1500 | 8 | 100 | 12000 |
+--------------+-------+----------+----------+-------------+
| Monitor | 12000 | 10 | 400 | 120000 |
+--------------+-------+----------+----------+-------------+
Deleting a View

A view can be deleted using DELETE command. Syntax for deleting a view without or with a condition
is as follows:

DELETE FROM VIEW view_name;

OR
DELETE FROM VIEW view_name WHERE condition;

For example,

DELETE FROM VIEW PRODUCT_SALES;
This command deletes all the rows from the view and from the table consequently.

DELETE FROM PRODUCT_SALES WHERE Discount = 400;
This command deletes the rows where Product_name is 'Monitor'. The view after the execution of
above command is as follows:

SELECT * FROM PRODUCT_SALES;
+--------------+-------+----------+----------+-------------+
| Product_name | Price | Quantity | Discount | Total_sales |
+--------------+-------+----------+----------+-------------+
| Laptop | 50000 | 5 | 500 | 250000 |
| Smartphone | 15000 | 10 | 1000 | 150000 |
| Headphones | 2500 | 15 | 300 | 37500 |
| Keyboard | 1500 | 8 | 100 | 12000 |
+--------------+-------+----------+----------+-------------+
Precaution must be taken while deleting values from the view as it results in deletion from the main

table as well, from which the view was created.
Consider another example:

CREATE VIEW STUDENT_1 AS

SELECT Adm_no, Name
FROM Stu
WHERE Name IS NOT NULL

WITH CHECK OPTION;

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Advanced Features of MySQL