ER model --Database Modeling >The eR data mode was developed to facilitate database design by allowing specification of an enterprise schema that represents the overall logical structure of a database >The ER model 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 concepts entity sets ° relationship sets, attributes >The ER model also has an associated diagrammatic representation the eR diagram, which can express the overall logical structure of a database graphicallyER model -- Database Modeling ➢The ER data mode was developed to facilitate database design by allowing specification of an enterprise schema that represents the overall logical structure of a database. ➢The ER model 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 concepts: • entity sets, • relationship sets, • attributes. ➢The ER model also has an associated diagrammatic representation, the ER diagram, which can express the overall logical structure of a database graphically