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

What is structured query langauge, What is Structured Query Langauge (SQL)?...

What is Structured Query Langauge (SQL)? SQL is a powerful set-oriented language which was formed by IBM research for the databases that adhere to the relational model. It havi

Demonstrate the uml model, Demonstrate the UML model Using UML, it is p...

Demonstrate the UML model Using UML, it is possible to generate code in any of the programming language from UML model (called forward engineering) and rebuild a model from an

What are called index-sequential files, What are called index-sequential fi...

What are called index-sequential files? The files that are ordered sequentially with a primary index on the search key are known as index-sequential files

Describe the static hash file with buckets and chaining, Describe the stati...

Describe the static hash file with buckets and chaining and show how insertion, deletion and modification of a record can be performed. In static hash file organization, the wo

Define a relation in dbms, Define a relation ? Relation - A relations...

Define a relation ? Relation - A relations is a named two-dimensional table of data. Mathematically, a relation can be described as a subset of the cartesian product of a lis

List the requirements needed to design a trigger, List the requirements nee...

List the requirements needed to design a trigger. The requirements are:- Specifying when a trigger is to be implemented. State the actions to be taken when the trigger im

Design a database table, A database named yourusernameFMA has been set up f...

A database named yourusernameFMA has been set up for you to use for this assignment.  For the FMA you must create the required tables and run the queries using this database.  If y

Explain the two types of participation constraint, Explain the two types of...

Explain the two types of participation constraint.  Total: The participation of an entity set E in a relationship set R is said to be total if each entity in E participates i

Datawarehouse Case studies, I have been given 8 differebt data warehouseing...

I have been given 8 differebt data warehouseing failure case studies. I need to question 4 questions for each

What are segments in oracle, What are segments in oracle? Segments - Ea...

What are segments in oracle? Segments - Each table has single field of disk space, known as segment, set aside for it in the tablespace. Segments consist of contiguous sections

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