Modify - referential integrity, Database Management System

Assignment Help:

Update or Modify operation alters the existing values. If these operations alter the value that is the foreign key also, the only check need is the similar as that of the Insert operation.

What should happen to an try to update a candidate key that is the objective of a foreign key reference? For instance, an attempt to update the PROJID "LG" for which there exists at least one matching ASSIGNMENT tuple? In common there are the similar possibilities as for DELETE operation:

RESTRICT: The update operation is "restricted" to the case where there are not matching assignment tuples. (it is rejected otherwise).

CASCADE - The update operation "cascades" to update the foreign key in those matching assignment tuples also.


Related Discussions:- Modify - referential integrity

What is the need of a log in a dbms, What is the need of a log in a DBMS? B...

What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log.            Ans:  The system log, which is generally writt

Define weak and strong entity sets, Define weak and strong entity sets?  ...

Define weak and strong entity sets?  Weak entity  set:  entity  set  that  do not  have  key  attribute  of  their  own are  known as weak entity sets.  Strong entity set

Project on designing and creating a database , This project will involve de...

This project will involve designing and creating a database for an organization.  In the design of a database, there is no single "perfect" design.  So your database design may not

What is alternate key, What is Alternate Key Alternate Key: This is t...

What is Alternate Key Alternate Key: This is the candidate key which is not taken as the primary key of the table. They are named so because although not the primary key, the

Define relations in tables and define primary keys, Consider the subsequent...

Consider the subsequent relations along with keys underlined Street (name, location, city) House (number, street_name) Lives (name, house_number) Define the above relations

Set concept is used in which type of modelling, SET concept is used in whic...

SET concept is used in which type of modelling? SET concept is used in Network Model.

Mysql database merge, MySQL Database Merge Project Description: I hav...

MySQL Database Merge Project Description: I have two databases, I need merge the data of one database into another Work to be done online right now. Payment can be done

Determine the advanced modeling concepts, Determine the Advanced modeling c...

Determine the Advanced modeling concepts You have to follow some steps for object-oriented design. These steps for OO Design methodology are as follow:  1)  Produce objec

Mention the several levels in security measures, Mention the several levels...

Mention the several levels in security measures. A) Database system B) Operating system C) Network D) Physical Human

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