The Entity-Relationship Model is often referred to as a
semantic data model, because it more closely resembles real
world scenarios than, e.g., the relational model.
. In the ER model, we model the concept of "Instructors."
In the relational model we deal with names and phone
numbers.
. In the ER model, there is a distinction between entities
(objects) and relationships between such entities.
In the relational model, both concepts are represented by
relations.
In software engineering, an Entity - Relationship model(ER model for short) is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called entity-relationship diagrams or ER diagrams.learn more www.ngprakasam.hpage.com
Explain data model?
In computer science, data modeling is the process of creating a data model by applying a data model theory to create a data model instance. A data model theory is a formal data model description.For the source and more detailed information concerning your request, click on the related links section (Answers.com) indicated below.
A database is a collection of tables that is used for some purpose (typically an application of some sort). A database model is a description of that database, and describes how the tables relate to each other. Typically, a model is designed first, then the actual database is implemented using the model as a blueprint.
Explain why nevigation is simple relational data model than in hirarchical 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.
The Entity-Relationship Model is often referred to as a semantic data model, because it more closely resembles real world scenarios than, e.g., the relational model. . In the ER model, we model the concept of "Instructors." In the relational model we deal with names and phone numbers. . In the ER model, there is a distinction between entities (objects) and relationships between such entities. In the relational model, both concepts are represented by relations.
An ER diagram is an "Entity Relationship" diagram, which illustrates the relationships between the entities in a data model. A data model for a timetable management system might have entities like Days, Periods and Rooms. Its ER Diagram would then show that a Day is broken down into multiple Periods, and each Room might be used for multiple Periods.
In software engineering, an Entity - Relationship model(ER model for short) is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called entity-relationship diagrams or ER diagrams.learn more www.ngprakasam.hpage.com
Because it is very useful in mapping the meanings and interactions of real-world enterprises onto a conceptual schema. Because of this usefulness, many database-design tools draw on concepts from the ER-model. The ER data model employs three basic notation:a.) Entity setsb.) Relationship setsc.) Attributes.
The data model identifies the objects/entities involved in the application and the relationships between them. From that, the ER diagram is solidified and this forms the basis of the database design.
The E-R model (Entity-Relationship model) is a visual representation of entities, attributes, and relationships in a database, while the relational model organizes data into tables with rows and columns. The E-R model focuses on the logical design of a database, while the relational model focuses on the physical implementation of data storage and retrieval. E-R model uses entities, attributes, and relationships to depict data structures, while the relational model uses tables, keys, and relationships to organize data.
Explain data model?
A data model is a collection of concepts that can be used to describe the structure of a database and provides the necessary means to achieve this abstraction whereas structure of a database means the data types,relationships and constraints that should hold on the data. Data model are divided into three different groups they are 1)object based logical model 2)record based logical models 3)physical models Types: Entity-Relationship (E-R) Data Model Object-Oriented Data Model Physical Data Model functional data model
Database is the collection records . There are three types of relationships in DB : one to one , one to many, many to many.
In computer science, data modeling is the process of creating a data model by applying a data model theory to create a data model instance. A data model theory is a formal data model description.For the source and more detailed information concerning your request, click on the related links section (Answers.com) indicated below.
The lowest data model is the physical data model. It represents how data is stored on a specific type of hardware and helps optimize storage and retrieval. It is the closest to the physical implementation in a database system.