difference between weak entity and strong entity pdf

Difference Between Weak Entity And Strong Entity Pdf

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An entity set is a collection or a set of all the entities that share the same attributes set but with a different set of values for some attributes. The entity can be classified into two basic categories:. A strong entity is an entity that is independent of any other entity in a schema.

Difference between Strong Entity and Weak Entity

What Is A Database Concurrency. Computer Fundamental Computer Intro. Information Tech. The entity set which does not have sufficient attributes to form a primary key is called as Weak entity set. An entity set that has a primary key is called as Strong entity set. Although each payment entity is distinct but payment for different loans may share the same payment number. Thus, this entity set does not have a primary key and it is an entity set.

What are Strong and Weak Entity Sets in DBMS.pdf

The entity set which does not have sufficient attributes to form a primary key is called as Weak entity set. An entity set that has a primary key is called as Strong entity set. Although each payment entity is distinct but payment for different loans may share the same payment number. Thus, this entity set does not have a primary key and it is an entity set. Each weak set must be a part of one-to-many relationship set. A member of a strong entity set is called dominant entity and member of weak entity set is called as subordinate entity. A weak entity set does not have a primary key but we need a means of distinguishing among all those entries in the entity set that depend on one particular strong entity set.

Skip to main content. Search form Search. Can weak entity have subclass. Can weak entity have subclass can weak entity have subclass This dependency is called existence dependency. Although each payment entity is distinct but payment for different loans may share the same payment number Weak Entity Sets An entity set with a primary key is a strong entity set.

In other words, ER diagrams help to explain the logical structure of databases. ER diagrams are created based on three basic concepts: entities, attributes and relationships. ER Diagrams contain different symbols that use rectangles to represent entities, ovals to define attributes and diamond shapes to represent relationships. At first look, an ER diagram looks very similar to the flowchart. However, ER Diagram includes many specialized symbols, and its meanings make this model unique.


A strong entity is not dependent of any other entity in the schema. A strong entity will always have a primary key. Strong entities are represented.


9 Difference Between Strong Entity Set And Weak Entity Set In DBMS (With Examples)

Talking about the Strong and Weak entity, we must know what does an entity means. An entity is a unique object in the real world. It is described as the set of attributes. The collection of the same type of entities together forms the entity set. Here, we will discuss two types of entities Strong entity and Weak entity.

A strong entity will always have a primary key. Strong entities are represented by a single rectangle. The relationship of two strong entities is represented by a single diamond. Various strong entities, when combined together, create a strong entity set.

ER Diagram: Entity Relationship Diagram Model | DBMS Example

Разные лаборатории приводят разные цифры.

Differentiate between Weak and Strong entity

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3 comments

Kimberly C.

We have learned about the Entity, Entity type, and Entity set.

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Justino S.

What Is A Database Concurrency.

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Landrada A.

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