DBMS Microproject 22319 Data Management System 3rd sem computer

DBMS Microproject 22319 Data Management System 3rd sem computer

program Name and Code: DBMS 22319 

Course Name and Code: CS 3I 

Academic Year : 

Semester: First

Annexure-I

A MICRO PROJECT ON " E-R diagram "

1.0   Aims/Benefits of the micro project

Database Management Systems (DBMS) are vital components of modern information systems.

Database applications are pervasive and range in size from small in-memory databases to terra

bytes or even larger in various application domains. The course focuses on the fundamentals of

knowledgebase and relational database management systems, and the current developments in

database theory and their practice.

2.0   Course outcome addressed.

a. Design a Normalized database on given data.

b. Create and Manage the Database using SQL command.

c. Write PL/SQL code for a given database.

d. Apply triggers to ob database and also create procedures and functions according to condition.

e. Apply security and confidentiality on the given Database.

3.0 Proposed methodology

1. Focused on the selection of an appropriate topic for the micro-project.

2. Select the topic i.e. To Prepare a report on the E-R diagram.

3. Brief study on our topic.

4. Gather all information based on the topic of the micro project.

5. Analysis and study of our topic in detail.

6. Following all the above methodologies we successfully completed our microproject.

4.0 Action Plan

Sr. No.	Detail of activity	Plan start date	Plan finish date	Name of responsible team members
1	Searching the topic for micro-project
2	collect information from the internet and textbook
3	collect information from the DBMS Data Management System reference book, and Debugged the errors.
4	arrange all information in ms word
5	Prepare a report on it using MS word
6	print micro project

5.0 Resources used

Sr. no.	Name of resource material	Specifications	Quantity
1	Computer System	8 GB RAM, Windows 10 OS	1
2	Internet	Youtube / Wikipedia
3	textbook/manual	DBMS  Data Management System	1

annexure-II
Micro-Project Report

A MICRO PROJECT ON "E-R diagram"

 1.0 Brief Introduction/Rationale

An Entity–relationship model (ER model) defines the structure of a database with the aid of a diagram, which is known as an Entity Relationship Diagram (ER Diagram). An ER model is a design or blueprint of a database that can later be executed as a database. The major components of the E-R model are the entity set and relationship set.

What is an Entity Relationship Diagram (ER Diagram)?

An ER diagram displays the relationship among entity sets. An entity set is a group of identical entities and these entities can have attributes. In terms of DBMS, an entity is a table or attribute of a table in the database, so by showing the relationship among tables and their attributes, ER diagram illustrates the complete logical structure of a database. Let's have a look at a simple ER diagram to comprehend this concept.

A simple ER Diagram:

In the following diagram, we have two entities Student and College, and their relationship. The relationship between Student and College is many to one as a college can have numerous students however a student cannot study in numerous colleges at the same time. Student entity has attributes such as Stu_Id, Stu_Name & Stu_Addr and College entity has attributes such as Col_ID & Col_Name.

Here are the geometric shapes and their significance in an E-R Diagram. 

Rectangle: Describes Entity sets.
Ellipses: Attributes
Diamonds: Relationship Set
Lines: They link attributes to Entity Sets and Entity sets to Relationship Set
Double Ellipses: Multivalued Attributes
Dashed Ellipses: Derived Attributes
Double Rectangles: Weak Entity Sets
Double Lines: Total participation of an entity in a relationship set

Elements of an ER Diagram

As displayed in the above diagram, an ER diagram has three major components:

1. Entity

2. Attribute

3. Relationship

1. Entity

An entity is an object or element of data. An entity is described as a rectangle in an ER diagram.

For example: In the following ER diagram we have two entities Student and College and these two entities have many to one relationship as many students study in a single college. We will read more about relationships later, but for now, concentrate on entities.

Weak Entity:

An entity that cannot be uniquely determined by its own attributes and relies on the relationship with another entity is called a weak entity. The weak entity is defined by a double rectangle. For example – a bank account cannot be uniquely determined without knowing the bank to which the account belongs, so bank account is a weak entity.

2. Attribute

An attribute defines the property of an entity. An attribute is expressed as an Oval in an ER diagram. There are four kinds of attributes:

1. Key attribute

2. Composite attribute

3. Multivalued attribute

4. Derived attribute

1. Key attribute:

A key attribute can uniquely recognize an entity from an entity set. For example, student roll numbers can uniquely determine a student from a set of students. The key attribute is defined by an oval same as other attributes however the text of the key attribute is highlighted.

2. Composite attribute:

An attribute that is a mixture of other attributes is known as a composite attribute. For example, In a student entity, the student address is a composite attribute as an address is composed of other attributes such as pin code, state, and country.

3. Multivalued attribute:

An attribute that can carry multiple values is known as a multivalued attribute. It is described with double ovals in an ER Diagram. For example – A person can have more than one phone number so the phone number attribute is multivalued.

4. Derived attribute:

A derived attribute is one whose value is dynamic and derived from another attribute. It is defined by a dashed oval in an ER Diagram. For example – A person's age is a derived attribute as it varies over time and can be derived from another attribute (Date of birth).

E-R diagram with multivalued and derived attributes:

3. Relationship

A relationship is described by a diamond shape in ER diagram, which indicates the relationship among entities. There are four kinds of relationships:
1. One to One
2. One to Many
3. Many to One
4. Many to Many

1. One-to-One Relationship

When a single instance of an entity is associated with a single instance of another entity then it is called one to one relationship. For example, a person has only one passport and a passport is given to one person.

2. One-to-Many Relationship

2.0  Actual Resources Use

Sr. no.	Name of resource material	Specifications	Quantity
1	Computer System	8 GB RAM, Windows 10 OS	1
2	Internet	Youtube / Wikipedia
3	textbook/manual	DBMS 22319	1

3.0 Skill Developed

1. Teamwork 

2. Communication skills 

3. Able to get all information about ER Diagram

Conclusion

An entity-relationship diagram, or ER diagram, is important for modeling the data held in a database. It is the basic design upon which a database is built. ER diagrams identify what data we will store: the entities and their attributes. They also illustrate how entities relate to other entities.

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