- Trending Categories
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Explain difference between Strong Entity and Weak Entity
Strong Entity
Strong Entity is independent to any other entity in the schema. A strong entity always have a primary key. In ER diagram, a strong entity is represented by rectangle. Relationship between two strong entities is represented by a diamond. A set of strong entities is known as strong entity set.
Weak Entity
Weak entity is dependent on strong entity and cannot exists without a corresponding strong. It has a foreign key which relates it to a strong entity. A weak entity is represented by double rectangle. Relationship between a strong entity and a weak entity is represented by double diamond. The foreign key is also called a partial discriminator key.
Following are some of the important differences between Strong Entity and Weak Entity.
| Sr. No. | Key | Strong Entity | Weak Entity |
|---|---|---|---|
| 1 | Key | Strong entity always have one primary key. | Weak entity have a foreign key referencing primary key of strong entity. |
| 2 | Dependency | Strong entity is independent of other entities. | Weak entity is dependent on strong entity. |
| 3 | Represented by | A strong entity is represented by single rectangle. | A weak entity is represented by double rectangle. |
| 4 | Relationship Representation | Relationship between two strong entities is represented by single diamond. | Relationship between a strong and weak entity is represented by double diamond. |
| 5 | Participation | Strong entity may or may not participate in entity relationships. | Weak entity always participates in entity relationships. |
- Related Articles
- Difference between Strong Entity and Weak Entity
- Difference Between Strong and Weak Entity
- Entity-Relationship Diagram
- HTML Entity Parser in C++
- Identifying Entity Relationships in DBMS
- Entity Integrity Rule in RDBMS
- Entity Relationship Participation in Database
- What is Entity-Relationship Modeling?
- Types of Entity Relationships in DBMS
- Extended Entity-Relationship (EE-R) Model
- Sodium carbonate is a basic salt because it is a salt of(a) strong acid and strong base(b) weak acid and weak base(c) strong acid and weak base(d) weak acid and strong base
- What are weak and strong electrolytes?
- How to identify entity from a given problem
- Importance of Entity-Relationship diagram in database design
- What is an Entity relationship model in DBMS?
Advertisements