Conversion of er diagram to relational database, Database Management System

Assignment Help:

Conversion of entity sets:

I)   For  every  strong  entity  type  E  in  the  ER  diagram,  we  make  a  relation  R containing all the easy attributes of E. The relation R primary key will be one of the key attributes of R.

For example, the STUDENT, FACULTY, COURSE and DEPARTMENT tables in Figure.

STUDENT

ROLLNO: Primary Key

NAME

ADDRESS

 

 

 

 

 

 


 

 

FACULTY

ID: Primary

Key

NAME

ADDRESS

BASIC_SAL

 

 

 

 

 

 

 

 

 

 

 

 

COURSE

COURSE_ID: Primary Key

COURSE_NAME

DURATION

 

 

 

 

 

 

 

DEPARTMENT

D_NO: Primary Key

 

 

 

 

 

For each weak entity type W in the E R Diagram, we make another relation R that have all easy attributes of W. If E is an owner entity of W then key attribute of E is also contained in R. This key attribute of R is set as a foreign key attribute of R. Now the mixture of primary key attribute of owner partial key and entity type of weak entity type will form the key of the weak entity type.

The weak entity GUARDIAN, where the key field of student entity

RollNo has been added.

RollNo            Name

(Primary Key)

Address

Relationship

 

 

 

 

 

 

 

 


Related Discussions:- Conversion of er diagram to relational database

Linear commit protocol, With the linear commit protocol, sites are connecte...

With the linear commit protocol, sites are connected in a chain, and the subtransaction at the left-hand end of the chain initiates the protocol. Propose a crash recovery protocol

Define shared locks, Define Shared locks? Ans: Shared lock: Throughout ...

Define Shared locks? Ans: Shared lock: Throughout concurrent execution of transactions, earlier than a transaction can access a data item, it has to obtain a lock on it. Now he

Draw an erd for the above relational schema, The following relational datab...

The following relational database schema represents part of a simplified database used by a library: tblBook (BookID, Title, PublisherID, Category,Price) tblPublisher (Publishe

Define query language, Define query language?   A query is a statement ...

Define query language?   A query is a statement requesting the retrieval of information. The portion of DML that includes information retrieval is known as a query language.

What function divides one numeric expression, What function divides one num...

What function divides one numeric expression by another and returns the remainder? MOD function divides one numeric expression by another and returns the remainder.

Delete - referential integrity, During the deletion of a tuple two cases ca...

During the deletion of a tuple two cases can happen: Deletion of tuple in relation having the foreign key: In this type of case simply delete the desired tuple. For example, in

Explain consistency model , Explain in detail the consistency model of the ...

Explain in detail the consistency model of the distributed file system you studied (GFS or AFS). Present the consistency model chosen and how it was achieved through design. Clarit

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

Describe the objective of structural diagrams, Describe the objective of St...

Describe the objective of Structural Diagrams The main objective of structural diagram is to visualize, construct, specify and document static aspects of a system. Their eleme

What is odbc, What is ODBC ? ODBC - Open DataBase Connectivity which i...

What is ODBC ? ODBC - Open DataBase Connectivity which is also denoted by ODBC enable the integration of SQL along with a common-purpose programming language. ODBC expose data

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