Create a database schema, Database Management System

Assignment Help:

Consider a database schema consisting of four relations, whose schemas are:

Product (maker, model, type)

PC (model, speed, ram, hd, price)

Laptop (model, speed, ram, hd, screen, price)

Printer (model, color, type, price)

The Product relation gives the manufacturer, model number and type (PC, laptop, or printer) of various products. (We assume for convenience that model numbers are unique over all manufacturers and product types; note that in reality, we can include a code for the manufacturer and product type as part of the model number.) The PC relation gives for each model number that is a PC, the speed (of the processor in GHz), the amount of RAM (in megabytes), the size of the hard disk  (in gigabytes), and the price. The Laptop relation is similar, except that the screen size (in inches) is also included. The Printer relation records for each printer model whether the printer produces color output (true or false), the process type (laser or ink-jet, typically), and the price.

Write the SQL CREATE TABLE (SQL DDL) statements for the above schema, specifying any primary key and unique constraints.

(Note that referential integrity ("foreign key") must ideally specify that the model in Product must appear in one of the PC, Laptop and Printer tables; we will learn how to specify such constraints later in the course using triggers; they cannot be specified using foreign key constraints - for this problem, you NEED NOT specify these constraints).

Include the SQL statements and appropriate screen shots showing that your CREATE TABLE statements succeeded into your submission document.


Related Discussions:- Create a database schema

How nulls are treated in comparison operator, How nulls are treated in comp...

How nulls are treated in comparison operator? Along with comparison (relational) operators, the null values are ignored as we cannot derive the relation along with the given op

Need for a database management system, NEED FOR A DATABASE MANAGEMENT SYSTE...

NEED FOR A DATABASE MANAGEMENT SYSTEM A Database is a structured, persistent collection of data of an organisation. The database management system (DBMS) manages the database o

Explain algorithm of er to relational mapping, Explain algorithm of ER To R...

Explain algorithm of ER To Relational Mapping ? ER-to-Relational Mapping Algorithm: 1) Step 1: Mapping of regular entity types: For each strong entity type E, form a relatio

Differentiate between a unique key and a primary key, Differentiate between...

Differentiate between a unique key and a primary key. - By default, clustered index on column are created by primary key while nonclustered index are created by unique key.

What are the two statements regarding transaction, What are the two stateme...

What are the two statements regarding transaction? The two statements regarding transaction of the form are:- A)     Begin transaction B)      End transaction

Define the term- control as state within program, Control as State within P...

Control as State within Program 1.  The term control exactly means to check effect of input within a program. For illustration, in Figure, after the ATM card is inserted (a

Explain the concept of qbe, Explain the concept of QBE? Query-by-exampl...

Explain the concept of QBE? Query-by-example represents a visual/graphical approach for accessing information in a database by the use of query templates called as skeleton tab

3NF Normalization, Need 2 projects completed in 3NF format.

Need 2 projects completed in 3NF format.

Consistency-transaction , Consistency: This property makes sure that a com...

Consistency: This property makes sure that a complete transaction implementation takes a database from one consistent state to another consistent state. If the transaction fails e

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