Creating views with check option-data control, Database Management System

Assignment Help:

Creating views with check option: This option limits those updates of data values that cause records to go off the view. The following instance tells this in more detail:

Example: To produce a view for employees of Department = 30, such that user cannot alter the department number from the view:

CREATE OR REPLACE VIEW EMPD30 AS

SELECT EMPNO EMPL_NUM, ENAME NAME, SAL SALARY FROM EMP

WHERE DEPTNO=30

WITH CHECK OPTION;

 

Now the user cannot alter the department number of any record of view EMPD30. If this change is permitted then the record in which the change has been made will go off the view as the view is only for department-30. This restricted due to use of WITH CHECK OPTION clause

 


Related Discussions:- Creating views with check option-data control

Advantages and disadvantages of using a database system, What are the advan...

What are the advantages and disadvantages of using a database system. Sol. Advantages of Database System (DBMS) :  (1) Data Redundancy and Inconsistency: Since differen

Advanced database systems, Consider an information system designed for an o...

Consider an information system designed for an online company which provides IT products and services These include desktops, laptops, networking products, IT books, parts, and

Sql, example of embedded SQL query

example of embedded SQL query

Illustrate the fifth normal form, Fifth Normal Form (5NF) These relatio...

Fifth Normal Form (5NF) These relations still have a difficulty. While defining the 4NF we mentioned that all the attributes depend upon each other. Whereas creating the two ta

Using relational algebra which query finds customers, Using Relational Alge...

Using Relational Algebra which query finds customers, who have a balance of over 1000 ? Using Relational Algebra Π Customer_name( σ balance >1000(Deposit)) is query to find cu

Oracle, List and explain the memory constructs of the Oracle 12c databases?...

List and explain the memory constructs of the Oracle 12c databases?

Types of online analytical processing tools, Describe the various types of ...

Describe the various types of Online Analytical Processing (OLAP) tools and briefly discuss how the support common analytical operations.

What is thread splitting, What is Thread splitting A thread of cont...

What is Thread splitting A thread of control is a path by which a set of state diagrams on that a single object is active at a time. Objects are shared between threads

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd