Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Extended Entity-Relationship Model

  • Bernhard ThalheimEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_157


EERM, HERM; Hierarchical entity-relationship model; Higher-order entity-relationship model


The extended entity-relationship (EER) model is a language for defining the structure (and functionality) of database or information systems. Its structure is developed inductively. Basic attributes are assigned to general base data types. Complex attributes can be constructed by applying constructors such as tuple, list, or set constructors to attributes that have already been constructed. Entity types conceptualize structuring of things of reality through attributes. Cluster types generalize types or combine types into singleton types. Relationship types associate types that have already been constructed into an association type. The types may be restricted by integrity constraints and by specification of identification of objects defined for a type. Typical integrity constraints of the extended entity-relationship model are participation, look-across, and general...

This is a preview of subscription content, log in to check access.

Recommended Reading

  1. 1.
    Chen PP. The entity-relationship model: toward a unified view of data. ACM Trans Database Syst. 1976;1(1):9–36.CrossRefGoogle Scholar
  2. 2.
    Embley D, Thalheim B, editors. Handbook of conceptual modelling: its usage and its challenges. Springer; Berlin 2011.Google Scholar
  3. 3.
    Gogolla M. An extended entity-relationship model – fundamentals and pragmatics. LNCS, vol. 767. Berlin: Springer; 1994.zbMATHCrossRefGoogle Scholar
  4. 4.
    Hartmann S. Reasoning about participation constraints and Chen’s constraints. In: The Fourteenth Australian Database Conference, Adelaide, Australia. Conferences in Research and Practice in Information Technology; 2003. p. 105–13.Google Scholar
  5. 5.
    Hartmann S, Hoffmann A, Link S, Schewe K-D. Axiomatizing functional dependencies in the higher-order entity-relationship model. Inf Process Lett. 2003;87(3):133–7.MathSciNetzbMATHCrossRefGoogle Scholar
  6. 6.
    Hohenstein U. Formale Semantik eines erweiterten Entity-Relationship-Modells. Stuttgart: Teubner; 1993.zbMATHCrossRefGoogle Scholar
  7. 7.
    Liddle SW, Embley DW, Woodfield SN. Cardinality constraints in semantic data models. Data Knowl Eng. 1993;11(3):235–70.zbMATHCrossRefGoogle Scholar
  8. 8.
    Schewe K-D, Thalheim B. Conceptual modelling of web information systems. Data Knowl Eng. 2005;54(2):147–88.CrossRefGoogle Scholar
  9. 9.
    Thalheim B. Dependencies in relational databases. Leipzig: Teubner; 1991.zbMATHCrossRefGoogle Scholar
  10. 10.
    Thalheim B. Entity-relationship modeling – foundations of database technology. Berlin: Springer; 2000.zbMATHCrossRefGoogle Scholar
  11. 11.
    Thalheim B. Codesign of structuring, functionality, distribution and interactivity. Aust Comput Sci Commun. 2004;31(6):3–12.Google Scholar
  12. 12.
    Thalheim B. Open problems of information systems research and technology. In: Proceedings of the 12th International Conference on Perspectives in Business Informatics Research. Lecture Notes in Business Information Processing; 2013. p. 10–8.Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Christian-Albrechts UniversityKielGermany