DBMS Concepts

DBMS Tutorial Components of DBMS. Applications of DBMS The difference between file system and DBMS. Types of DBMS DBMS Architecture DBMS Schema Three Schema Architecture. DBMS Languages.

DBMS ER Model

ER model: Entity Relationship Diagram (ERD) Components of ER Model. DBMS Generalization, Specialization and Aggregation.

DBMS Relational Model

Codd’s rule of DBMS Relational DBMS concepts Relational Integrity Constraints DBMS keys Convert ER model into Relational model Difference between DBMS and RDBMS Relational Algebra DBMS Joins

DBMS Normalization

Functional Dependency Inference Rules Multivalued Dependency Normalization in DBMS: 1NF, 2NF, 3NF, BCNF and 4NF

DBMS Transaction

What is Transaction? States of transaction ACID Properties in DBMS Concurrent execution and its problems DBMS schedule DBMS Serializability Conflict Serializability View Serializability Deadlock in DBMS Concurrency control Protocols

Difference

Difference between DFD and ERD

Misc

Advantages of DBMS Disadvantages of DBMS Data Models in DBMS Relational Algebra in DBMS Cardinality in DBMS Entity in DBMS Attributes in DBMS Data Independence in DBMS Primary Key in DBMS Foreign Key in DBMS Candidate Key in DBMS Super Key in DBMS Aggregation in DBMS Hashing in DBMS Generalization in DBMS Specialization in DBMS View in DBMS File Organization in DBMS What Is A Cloud Database What Is A Database Levels Of Locking In DBMS What is RDBMS Fragmentation in Distributed DBMS What is Advanced Database Management System Data Abstraction in DBMS Checkpoint In DBMS B Tree in DBMS BCNF in DBMS Advantages of Threaded Binary Tree in DBMS Advantages of Database Management System in DBMS Enforcing Integrity Constraints in DBMS B-Tree Insertion in DBMS B+ Tree in DBMS Advantages of B-Tree in DBMS Types of Data Abstraction in DBMS Levels of Abstraction in DBMS 3- Tier Architecture in DBMS Anomalies in Database Management System Atomicity in Database Management System Characteristics of DBMS DBMS Examples Difference between Relational and Non-Relational Databases Domain Constraints in DBMS Entity and Entity set in DBMS ER Diagram for Banking System in DBMS ER Diagram for Company Database in DBMS ER Diagram for School Management System in DBMS ER Diagram for Student Management System in DBMS ER Diagram for University Database in DBMS ER Diagram of Company Database in DBMS Er Diagram Symbols and Notations in DBMS How to draw ER-Diagram in DBMS Integrity Constraints in DBMS Red-Black Tree Deletion in DBMS Red-Black Tree Properties in DBMS Red-Black Tree Visualization in DBMS Redundancy in Database Management System Secondary Key in DBMS Structure of DBMS 2-Tier Architecture in DBMS Advantages and Disadvantages of Binary Search Tree Closure of Functional Dependency in DBMS Consistency in Database Management System Durability in Database Management System ER Diagram for Bank Management System in DBMS ER Diagram for College Management System in DBMS ER Diagram for Hotel Management System in DBMS ER Diagram for Online Shopping ER Diagram for Railway Reservation System ER Diagram for Student Management System in DBMS Isolation in DBMS Lossless Join and Dependency Preserving Decomposition in DBMS Non-Key Attributes in DBMS Data Security Requirements in DBMS DBMS functions and Components What is Homogeneous Database? DBMS Functions and Components Advantages and Disadvantages of Distributed Database Relational Database Schema in DBMS Relational Schema

Entity and Entity set in DBMS
2023-03-07 16:51:02

Entity and Entity set in DBMS

What is DBMS?

A database management system (DBMS) is a software application that interacts with end-users, other applications, and the database itself to capture and analyze the data. A DBMS allows users to create, read, update and delete databases, as well as control access to the data stored in it. It provides an interface for managing data, including data definition, data insertion, data manipulation, data query, and data access.

There are 2 main types of DBMS, relational and non-relational DBMS. RDBMS (Relational DBMS) uses a relational model to organize data into tables with rows and columns, having each table as a unique primary key. On the other hand, Non-relational DBMS (NoSQL) uses a variety of data models, such as document, key-value, graph, or column, and does not follow the relational model.

Examples of DBMS include MySQL, Oracle, Microsoft SQL Server, PostgreSQL, MongoDB, and Cassandra.

DBMS is widely used in various fields like banking, healthcare, e-commerce, and many more. It helps in managing large amount of data, data integrity, data security, data recovery, and many more.

Types of sets in DBMS

In a database management system (DBMS), there are several types of sets that can be used to organize and represent data:

Entity sets: It represents a collection of entities of the same type. It is a logical grouping of related entities, and it is defined by a set of attributes and a set of relationships.

Record or Tuple sets: It represents a collection of records or tuples that satisfy a specific query or condition. It is a subset of the database that is selected based on certain criteria.

Attribute sets: It represents a collection of attributes that describe an entity. An attribute set can be thought of as a column in a table, with each element representing a unique attribute of an entity.

Domain sets: It represents a collection of possible values that an attribute can take. Each attribute has an associated domain set that defines the set of acceptable values for that attribute.

Relationships set: It represents a collection of relationships between entities. Relationships can be one-to-one, one-to-many, or many-to-many, and they are represented by foreign keys that link one table to another.

Data sets: It represents a collection of data, which is the actual information stored in the database. A data set can be thought of as a table in a database, with each row representing a unique data entry and each column representing an attribute of that data entry.

What is an Entity?

In a database management system (DBMS), an entity is a real-world object or concept that is represented within the database. An entity can be a person, place, thing, or event, and it is represented by one or more tables in the database. Each table represents a different aspect or attribute of the entity. For example, in a database of employees, the entity would be "employee" and the table would contain information about the employee such as their name, address, and salary.

Entities are also related to each other, resulting in relationships. In a database, these relationships are represented by foreign keys, which link one table to another. Relationships can be one-to-one, one-to-many, or many-to-many. Entities can also be classified into two types: dependent and independent entities. Dependent entities are those that cannot exist without the independent entities.

What is an Entity set?

In a database management system (DBMS), an entity set is a collection of entities of the same type. It is a logical grouping of related entities, and it is defined by a set of attributes and a set of relationships. For example, in a database of employees, the entity set would be "employees" and it would contain all the entities of type "employee."

An entity set can also be thought of as a table in a database, with each row representing a unique entity and each column representing an attribute of that entity. Each entity in an entity set has a unique identifier, called a primary key, which is used to distinguish one entity from another within the set.

In a database schema, an entity set is represented by a rectangle, with the name of the entity set written inside. The attributes of the entity set are represented by ovals connected to the rectangle by lines. The relationships between entities sets are represented by diamonds, connected to the rectangles representing the entity sets.