this book provides an overview of database modeling with the Entity-Relationship (ER) model and the relational model. The book focuses On the primary achievements in relational database theory, including query languages, integrity constraints, database design, computable queries; and concurrency control.The first answer is that the ER model provides the flexibility to model real-world enterprises in several different ways. ... it to its entity type by a double line; see Figure 2.1 for examples of single-valued and multi-valued attributes in an ERD.
|Title||:||A Guided Tour of Relational Databases and Beyond|
|Author||:||Mark Levene, George Loizou|
|Publisher||:||Springer Science & Business Media - 1999-05-28|