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

Differentiate between a global and a local temporary table, Differentiate b...

Differentiate between a Global and a Local temporary table? - A local temporary table exists only for the duration of a connection or if defined inside a compound statement, fo

What is the use of group by clause, What is the use of group by clause? ...

What is the use of group by clause? Group by clause is used to be relevant aggregate functions to a set of tuples. The attributes given in the group by clause are used to shape

Define transitive dependencies, What do you understand by transitive depend...

What do you understand by transitive dependencies? Define with an example any two problems that can take place in the database if transitive dependencies are available in the datab

Write the sql code, Express the following queries in SQL: (a) Write the...

Express the following queries in SQL: (a) Write the SQL code that will create ALL the four tables given in the appendix. Your answer should not contain the primary key and

What is called as recursive partitioning, What is called as recursive parti...

What is called as recursive partitioning? The system repeats the splitting of the input unless each partition of the build input fits in the memory. Such partitioning is known

Introduction to Database Design and Development, Every School has many teac...

Every School has many teachers and many students. Each student is assigned to one school and each teacher works for one school only. Each teacher teaches more than one subject but

Many-to-many relationship, Many-to-many : Entities in A and B are related w...

Many-to-many : Entities in A and B are related with any number of entities from each other. Example: Taught_by Relationship among course and faculty. One faculty member ca

What is the use of sub queries, What is the use of sub queries? A sub q...

What is the use of sub queries? A sub query is a select-from-where expression that is nested with in another query. A common use of sub queries is to do tests for set membershi

Sequences-data control, Sequences Sequences: Automatically produ...

Sequences Sequences: Automatically produce unique numbers Are sharable Are typically used to make a primary key value Replace application code Speed up t

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