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 function of a domain, What is the function of a Domain? A d...

What is the function of a Domain? A domain defines the technical settings of a table field. A domain describes a value range, which sets the permissible data values for the

Oracle SQL Developer, Introductory course and so does not require any fancy...

Introductory course and so does not require any fancy coding. I will provide a guidance document to help you in producing the solutions.

Project, I need help in doing my dbms project

I need help in doing my dbms project

What is an e-r model and draw an e-r diagram for the company, What is an E-...

What is an E-R model? Draw an E-R Diagram for the company database with following Descriptions? The company is organized within departments. Each department has a unique name a

NORRMALIZATION, Home based assignment Consider an ORDER table with the foll...

Home based assignment Consider an ORDER table with the following attributes: • Order Number (ONo),Customer Number (CNo),Customer Name (CNa),Item Number (INo),Unit Price (UP), Quant

What are the problems in database normalization, What are the problems if o...

What are the problems if one were not to normalize?  When do these problems surface?           Ans:  Database normalization, sometimes considered to as  canonical synthesis, is

Database ass1, #quCreate a database design specification (Enhanced Entity R...

#quCreate a database design specification (Enhanced Entity Relationship Diagram (EERD) and Relational Data Model (RDM)) from the given business description. The RDM must be in 3rd

Online Bakery Data Base Project, How much would you charge to create a data...

How much would you charge to create a database encompassing an Online Bakery with all the elements below? I. Describe the application that you would like to design. This should

Define functional and multivalued dependencies, Define functional and multi...

Define functional and multivalued dependencies.       Ans:  A functional dependency is a assets of the semantics of the attributes in a relation. The semantics point out how at

Multi-key file organisation, Multi-Key File Organisation In this part, ...

Multi-Key File Organisation In this part, we will introduce two basic file Organisation schemes that permit records to be accessed by more than one key field, therefore, allowi

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