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Entities and attributes unable you to explicitly define what information, or data, is being
stored in the database. Relationships are the other powerful feature of relational modeling
and give the modeling technique its name. A relationship is a logical linkage between two
entities that describes how those entities are associated with each other. Think of
relationships as the logical links in a database that turn simple data into useful information.
For instance, our definition of a teacher reads: “A person employed by the college who is
responsible for instructing students in a class.”
Wiki User
∙ 11y ago
Entities are the objects or concepts that we want to store data about, while attributes are the characteristics or properties of those entities. Each entity can have multiple attributes that describe different aspects of the entity. Attributes provide details about entities and help to define their unique features within a database or system.
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What is the difference between associative entity and relationship with attribute?
An associative entity is used to represent a many-to-many relationship between two or more entities in a database, while a relationship with attribute represents additional information or properties about the relationship itself. In other words, an associative entity helps in resolving many-to-many relationships, while a relationship with attribute adds details about the connections between entities.
What Data model is said to be a semantic data model?
An Entity-Relationship (ER) model is commonly referred to as a semantic data model. It focuses on defining the entities, attributes of the entities, and the relationships between entities to capture the meaning of data in a domain. This model helps to visualize and understand the semantics of the data being represented.
What are the different types of information represented in the ER diagram and the symbols used to represent them?
The different types of information represented in an ER diagram are entities (represented by rectangles), attributes (represented by ovals connected to entities), and relationships between entities (represented by diamonds). Entities are the objects or concepts about which data is stored, attributes are the properties of entities, and relationships define how entities are connected to each other.
What are the Names of the types of data models in an ER diagram in the proper sequence they should be created?
In an ER diagram, the types of data models created in sequence are entities, attributes, relationships, and constraints. Entities represent the real-world objects, attributes describe the properties of entities, relationships establish connections between entities, and constraints define rules for the relationships or attributes. This sequence helps in organizing the structure and relationships of the data model effectively.
When do you have to use an intersection entity in database?
An intersection entity is used in a database when there is a many-to-many relationship between two entities. It serves as a bridge table to resolve the many-to-many relationship by breaking it into two one-to-many relationships. Each record in the intersection entity represents a combination of records from the two related entities.
Why associative entity use in ER model?
Associative entities are used in Entity-Relationship (ER) models to represent relationships between two or more entities. They help to model complex relationships that have attributes of their own. By using associative entities, we can accurately capture the associations between the main entities and represent them in a clear and normalized way.
Binary relationship in database?
A binary relationship is a type of relationship between the entities, which links to types of entities in it.
What should be the erd for website design?
ERD is an Entity Relationship Diagram which is a graphical representation of database entities (tables, table columns, table definitions, attributes) and inter-relationships between these entities (how the tables are connected).
How to draw entity relationship diagram?
To draw a relationship diagram, start by placing relationship at the center of the paper. Connect entities to the relationship, and branch out with the different attributes.
What is the difference between associative entity and relationship with attribute?
An associative entity is used to represent a many-to-many relationship between two or more entities in a database, while a relationship with attribute represents additional information or properties about the relationship itself. In other words, an associative entity helps in resolving many-to-many relationships, while a relationship with attribute adds details about the connections between entities.
An association between entities is known as?
A relationship.
What is the meaningful relationship between entities?
It is when 2 entities bang each other really hard
What Data model is said to be a semantic data model?
An Entity-Relationship (ER) model is commonly referred to as a semantic data model. It focuses on defining the entities, attributes of the entities, and the relationships between entities to capture the meaning of data in a domain. This model helps to visualize and understand the semantics of the data being represented.
What are the different types of information represented in the ER diagram and the symbols used to represent them?
The different types of information represented in an ER diagram are entities (represented by rectangles), attributes (represented by ovals connected to entities), and relationships between entities (represented by diamonds). Entities are the objects or concepts about which data is stored, attributes are the properties of entities, and relationships define how entities are connected to each other.
What are the characteristics of data model?
A data model specifies the rules and concepts on how to represent objects, their descriptions and how they relate. As such, the data model gives the definitions of the attributes and entities, specifies the datatypes of attributes and give relationships between entities.
What are the Names of the types of data models in an ER diagram in the proper sequence they should be created?
In an ER diagram, the types of data models created in sequence are entities, attributes, relationships, and constraints. Entities represent the real-world objects, attributes describe the properties of entities, relationships establish connections between entities, and constraints define rules for the relationships or attributes. This sequence helps in organizing the structure and relationships of the data model effectively.
What is relationship in er diagram?
In Database Analysis and Design; the relationship in an ERD can only be mandatory or optional between two entities. Mandatory is where both entities must be present, whereas with optional, you don't always need two entities.
