Subclassing, Database Management System

Assignment Help:

In the ER diagram, one example of subclassing is depicted following the Services entity. The subclasses Item Based and Time Based are created. The entity Services gains the attribute priceID depending on the price of the service. For example, a time based service is measured hourly so its price is adjusted to the priceID. This information is gained and placed into the Service entity to make the Payments entity exist and function.


Related Discussions:- Subclassing

Describe queries with complex types, Describe queries with complex types? ...

Describe queries with complex types? The present extension of the SQL query language deal with the complex type Let us start with the simple example: Find the title and t

Assignment, What are the typical phases of query processing

What are the typical phases of query processing

A basic model of database access control, A basic model of Database Access ...

A basic model of Database Access Control Models of database access control have grown out of previous work on protection in operating systems. Let us talk about one simple mode

Construct a generalization-specialization hierarchy, Construct a generaliza...

Construct a generalization-specialization hierarchy for a motor-vehicle sales company. The company sells motorcycles that comprise an engine number and cost; cars that have a chass

Hashed file organisation, Hashed File Organisation Hashing is the most ...

Hashed File Organisation Hashing is the most common form of purely random access to a database or file. It is also used to access columns that do not have an index as an optimi

Implementation of database, The ER diagram clearly showing the additional t...

The ER diagram clearly showing the additional tables you have implemented. SQL table creation scripts for the tables you have set up. SQL scripts showing the sample data you

What is the use of keyword isa, What is the use of keyword ISA? The use...

What is the use of keyword ISA? The use of keyword ISA is to show that a class is a specialization of another class.

Data definition language, Data Definition Language It organises the dat...

Data Definition Language It organises the data in the form of columns and rows. But what does the data field column of table accumulate? How do you describe it using SQL? Th

Lossless-join decomposition, Lossless-Join Decomposition   Let us sh...

Lossless-Join Decomposition   Let us show an intuitive decomposition of a relation. We require a better basis for deciding decompositions since intuition may not always be r

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