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

Develop a java application, 1 - Serial RS232 comm port comunication 2 - ...

1 - Serial RS232 comm port comunication 2 - NanoHTTPD serving a few processed pages 3 - System tray application to indicate status and access configuration forms 4 - SQLit

Describe integrity and security, Describe integrity and security? a)   ...

Describe integrity and security? a)      Domain constraint b)      Referential integrity A value that appears in one relation for a given set of attributes also appear fo

Create student db and retrieve all student name in cs, Create a Student dat...

Create a Student database and Retrieve the names of all students majoring in ‘CS' Consider the following relational database: STUDENT (name, student#, class, major) COURSE (co

Normalization, Normalize the given relation to 3NF, justifying each step

Normalize the given relation to 3NF, justifying each step

Data warehousing and business intelligence, I need help with data warehousi...

I need help with data warehousing and business intelligence course project about designing a data warehouse for a jewelry company that does not have one

Er diatgrams, Ask q“A database will be made to store information about pati...

Ask q“A database will be made to store information about patients in a hospital. On arrival, each patient’s personal details (name, address, and telephone number) are recorded wher

What is primary key explain, What is primary Key Explain? Primary Key ...

What is primary Key Explain? Primary Key - Primary key is one of the candidate keys. It should be selected such in which its attribute values are never, or very rarely, chang

Types of locks, Types of Locks There are two necessary types of locks: ...

Types of Locks There are two necessary types of locks: Binary lock : This locking mechanism has two states for to a data item: locked or unlocked Multiple-mode loc

Eliminate redundant data, Eliminate Redundant Data In the "Database Rel...

Eliminate Redundant Data In the "Database Relation" above, the primary key is made up of the D-ID and the Emp-ID. The database-name relies only on the D-ID. The similar databas

Mention the several levels in security measures, Mention the several levels...

Mention the several levels in security measures. A) Database system B) Operating system C) Network D) Physical Human

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