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

Assignment topic, assume we have the following apllicationthat model sccer ...

assume we have the following apllicationthat model sccer team the games they play and the players inv each teamin the design we want to capture

Design a gennalization and specialization hierarchy for an a, Design a genn...

Design a gennalization and specialization hierarchy for an automobile sales company

Explain the term- signal-to-noise ratio, Explain the term- signal-to-noise ...

Explain the term- signal-to-noise ratio A signal-to-noise ratio of 20 dB means that S/N = 100. As log2101 is around 6.658, the Shannon limit is around 19.975 kbps. The Nyquist

Entity integrity constraint - relational constraints, It defines that no pr...

It defines that no primary key value can be null. This is as the primary key is used to recognize individual tuple in the relation. So we will not be able to recognize the records

What is a virtual table that draws its data from the result, What is a virt...

What is a virtual table that draws its data from the result of an SQL SELECT statement? View is a virtual table that draws its data from the result of an SQL SELECT statement.

Record based logical models, Record based Logical Models: Use records as th...

Record based Logical Models: Use records as the key data representation components Examples: Relational Model: It shows data as well as relationship between data in the form

The tools that are available for managing mysql server, Describe the tools ...

Describe the tools that are available for managing MySQL Server. Given below are the tools to manage MySQL server: mysqld - MySQL server daemon. This is used to begain t

Equi-join, explain equi-join using illustration

explain equi-join using illustration

Field, examples of fields in a database

examples of fields in a database

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