Binary relationships, Database Management System

Assignment Help:

One-to-one relationship:

For every 1:1 relationship type R in the ER diagram including two entities E1 and E2 we take one of entities (say E1) preferably with total participation and add primary key attribute of one more entity E2 as a foreign key attribute in the table of entity (E1). We will also have all the simple attributes of relationship type R in E1 if any.

For instance, the DEPARTMENT relationship has been extended to contain head-Id and attribute of the relationship. Please note we will maintain information in this table of only present head and Date from which s/he is the head.

There is one Head_of 1:1 relationship among FACULTY and DEPARTMENT. We select DEPARTMENT entity having total participation and add primary key attribute ID of FACULTY entity as a foreign key in DEPARTMENT entity named as Head_ID. Now the DEPARTMENT table will be as follows:

DEPARTMENT

D_NO

D_NAME

Head_ID

Date-from

 

 

 

 

 

 

 

 


Related Discussions:- Binary relationships

Adding redundant associations for efficient access, Adding Redundant Associ...

Adding Redundant Associations for Efficient Access Redundant associations do not add any type of information, therefore during design we should actually examine structure of o

Dbms, statical data

statical data

Developer competent in data cleansing-data scrubbing, Data Scrubbing 70,000...

Data Scrubbing 70,000 records Project Description: We need services of a developer competent in data cleansing/Data scrubbing. Scope: - 70,000 records in CSV format.

Differences between a file processing system and a dbms, List any two signi...

List any two significant differences between a file processing system and a DBMS. File Processing System vs. DBMS Data Independence - Data independence is the capacity t

E - r schema with weak entity, Consider the E/R schema with weak entity set...

Consider the E/R schema with weak entity sets shown below. Come up with the SQL CREATE TABLE statements (with appropriate primary key, unique and foreign key constraints). Include

Inconsistent analysis-problems of concurrent transactions, Inconsistent Ana...

Inconsistent Analysis : The problem as given with transactions T1 and T2 where two transactions interleave to make incorrect result during an analysis by Audit is the instance of s

What is the archtetype pattern, What is the archtetype/instance pattern? ...

What is the archtetype/instance pattern? The archetype/instance pattern happens when one entity tracks occurrences of another entity. A common example is the relationship among

What is candidate key, What is candidate key? Candidate Key - A candi...

What is candidate key? Candidate Key - A candidate key of an entity set is a minimal superkey, which uniquely identifies each row in the relation.

I need label printing program, Project Description: Hi I'm seeking someo...

Project Description: Hi I'm seeking someone to make my dBase application work. I know it's not a 'modern' language but it's what I know. I have written an order program and I ne

Which component of dbms can be embedded in a program, which component of DB...

which component of DBMS can be embedded in a program? The data manipulation language (DML) is a component which is embedded in a program.

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