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

Example database application, We will explain here an example database appl...

We will explain here an example database application having COLLEGE database and use it in showing several E-R modelling concepts. College database remains track of faculty, Stu

Give example of relational schema, An instance of relational schema R (A, B...

An instance of relational schema R (A, B, C) has distinct values of A including NULL values. then A is a candidate key or not? If relational schema R (A, B, C) has distinct val

Consistency, what do you mean by consistency in rdbms?

what do you mean by consistency in rdbms?

What is distributed system, What is Distributed system ? Distributed S...

What is Distributed system ? Distributed System - A distributed system consists of a number of processing parts in which are interconnected through a computer network and in

Creating views with check option-data control, Creating views with check op...

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: Examp

Define the concept of aggregation, Define the concept of aggregation.  Give...

Define the concept of aggregation.  Give two examples where this concept is useful. Ans: Aggregation transforms a relationship among the objects into a higher-level object. A

Which language used in application programs for request data, Which languag...

Which language used in application programs to request data from the DBMS is referred? Language which is used in application program is DML to request data from the DBMS is ref

What is object containment, What is object containment? References amon...

What is object containment? References among objects can be used to model dissimilar real-world concepts.

Discuss the mechanism to read data from and write to a disk, Discuss the me...

Discuss the mechanism to read data from and write to a disk? Disk read/write heads are mechanisms in which read data from or write data to disk drives. The heads have gone by

What are the different integrity constraints in rdbms, What are the differe...

What are the different integrity constraints in RDBMS? The various integrity constraints in RDBMS are as: Primary Key: primary key is a grouping of one or more attributes

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