entity-relationship model

(redirected from ER model)

entity-relationship model

(database, specification)
An approach to data modelling proposed by P. Chen in 1976. The model says that you divide your database in two logical parts, entities (e.g. "customer", "product") and relations ("buys", "pays for").

Entity-relationship diagrams can be used to represent a model.

["The entity-relationship model: toward a unified view of data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp 9-36, 1976].
References in periodicals archive ?
Concentration-response data from 18 ER HTS assays were integrated into an ER model, the output of which provides a score of potential ER agonist and antagonist activity, chemical potency, and a measure of assay-specific false positive activity of each chemical run in ToxCast[TM] (Judson et al.
Aqua Data Studio's Entity-Relationship Modeler has also been extended, and now has the ability to convert or translate an ER model from one database to another, along with the ability to export to ERX format, import object schemas into existing databases and compare schema objects of different models within the same or different databases.
For example, the birthdate and deathdate attributes in the Barker ER model shown in Figure 1.
Strategies in modeling with regard to the data warehouse ER model, the data warehouse dimensional model and the independent data marts as described by Jukic (2006) are explored and practiced in the classroom setting.
The recent Unified Modeling language-2 (UML 2) has relation with the ER model and this is deployed in the chapter on Unified Modelling Language.
The student responses to the questionnaire suggested that most students appreciated the feature of being able to view the complete ER model.
The combination of 'employment arrangements' and 'value of HR to firm' form the foundation of the ER model presented in Figure 2.
Since its inception, the ER model has undergone many additions and enhancements that increase its expressive power and obtain better conceptual designs [Batini et al.
For example, Peter Chen's original ER model offers Entity, Relationship and Attribute as primitive terms, supports a limited form of classification (because entities and relationships are instances of entity and relationship types), offers primitive operations for creating new entity or relationship types or instances thereof, and supports cardinality constraints for relationships, such as "every child has up to two parents.
Tenders are invited for Raising of ER Model Plantation during 2016-17 Sagar Range, Anvatti Range and Ambligola
In the ER model, for example, Elmasri and Navathe [1994] sometimes represent them as weak entity types and sometimes as attributes.