Relationship for college database, Database Management System

Assignment Help:

Using the concepts defined previous, we have identified that strong entities in COLLEGE database are FACULTY, STUDENT, COURSE and DEPARTMENT. This database also has one weak entity known as GUARDIAN. We can states the following relationships:

1. Head-of is a 1:1 relationship among FACULTY and DEPARTMENT.

Participation of the entity FACULTY is partial since not all the faculty members participate in this relationship, as the participation from department side is total, as every department has one head.

2. Works_in, is a 1:N relationship among DEPARTMENT and FACULTY.

Participation from both sides is total.

3. Opts, is a 1:N relationship among COURSE and STUDENT. Participation from student side is total because we are assuming that every student enrolled opts for a course. However the participation from the course side is partial, as there can be courses that no student has opted for.

4. Taught_by, is a M: N relationship between FACULTY and COURSE, as a faculty can teach a lot of courses and a course can be taught by a lot of faculty members.

5. Enrolled, is a 1: N relationship among STUDENT and DEPARTMENT as a student is allowed to enroll for only single department at a time.

6. Has, is a 1:N relationship among STUDENT and GUARDIAN as a student can have more than one local guardian and one local guardian is supposed to be related to one student only. The weak entity Guardian has total participation in the relation "Has".


Related Discussions:- Relationship for college database

Explain the structure of well formed formulae, Explain the structure of wel...

Explain the structure of well formed formulae in relational calculus. Ans: a. An atom is a formula b. If P1 is a formula, after that so are ¬P1 and (P1) c. If P1 and P2 a

Explain dynamic two-phase locking, Explain Dynamic Two-Phase Locking H...

Explain Dynamic Two-Phase Locking Here a transaction locks a data item instantly earlier than any operation is applied on the data item.  After finishing all the operations on

Optimistic concurrency control, Optimistic Concurrency Control Is locki...

Optimistic Concurrency Control Is locking the only way to stop concurrency related problems? There exist some other ways too. One such way is known as an Optimistic Concurrency

Ddl compiler-database management system, DDL Compiler The DDL compile...

DDL Compiler The DDL compiler changes the data definition statements (such as CREATE TABLE .... in SQL) into a set of tables having metadata tables. These tables have infor

Extended star schema model, A customer places orders for parts and belongs ...

A customer places orders for parts and belongs to a particular industry group. An individual order is taken by a particular sales representative on a specific date and the sales re

Describe the grant function and explain security, Describe the GRANT functi...

Describe the GRANT function and explain, how it associates to security. What kind of privileges may be granted? How are they revoked? Ans: Since more than one user can aacce

Explain p command in the respect of qbe, Explain P command in the respect o...

Explain P command in the respect of QBE? P: It is the command in which is used to print (logically display) the value of the attribute in whose cell it is writ

What are the advantages of having an index structure, What are the advantag...

What are the advantages of having an index structure?      Ans: The index structures commonly provide secondary access paths, which offer alternative ways of accessing the reco

Characteristics, what are the main characteristics of database

what are the main characteristics of database

Confirming.., I just purchased a document for you guys and wanted to confir...

I just purchased a document for you guys and wanted to confirm that it will be send within an hour or 2 to my email or where will document be sent to?

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