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Extended Entity-Relationship Model


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...


  • EER Model
  • Extended Entity-Relationship (EER)
  • Basic Generic Types
  • General Cardinality Constraints
  • Constraint Card

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Recommended Reading

  1. Chen PP. The entity-relationship model: toward a unified view of data. ACM TODS. 1976;1(1):9–36.

    CrossRef  Google Scholar 

  2. Embley D, Thalheim B, editors. Handbook of conceptual modelling: its usage and its challenges. Springer; Berlin 2011.

    Google Scholar 

  3. Gogolla M. An extended entity-relationship model – fundamentals and pragmatics. LNCS, vol. 767. Berlin: Springer; 1994.

    Google Scholar 

  4. Hartmann S. Reasoning about participation constraints and Chen’s constraints. In: ADC. CRPIT, vol. 17. Australian Computer Society; 2003. p. 105–13.

    Google Scholar 

  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.

    MathSciNet  CrossRef  MATH  Google Scholar 

  6. Hohenstein U. Formale Semantik eines erweiterten Entity-Relationship-Modells. Stuttgart: Teubner; 1993.

    CrossRef  MATH  Google Scholar 

  7. Liddle SW, Embley DW, Woodfield SN. Cardinality constraints in semantic data models. Data Knowl Eng. 1993;11(3):235–70.

    CrossRef  MATH  Google Scholar 

  8. Schewe K-D, Thalheim B. Conceptual modelling of web information systems. Data Knowl Eng. 2005;54:147–88.

    CrossRef  Google Scholar 

  9. Thalheim B. Dependencies in relational databases. Leipzig: Teubner; 1991.

    CrossRef  MATH  Google Scholar 

  10. Thalheim B. Entity-relationship modeling – foundations of database technology. Berlin: Springer; 2000.

    CrossRef  MATH  Google Scholar 

  11. Thalheim B. Codesign of structuring, functionality, distribution and interactivity. Aust Comput Sci Commun. 2004;31(6):3–12. Proceedings of APCCM’2004.

    Google Scholar 

  12. Thalheim B. Open problems of information systems research and technology. In: BIR’2013. LNBIB. Springer; 2013. p. 10–8.

    Google Scholar 

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Correspondence to Bernhard Thalheim .

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Thalheim, B. (2017). Extended Entity-Relationship Model. In: Liu, L., Özsu, M. (eds) Encyclopedia of Database Systems. Springer, New York, NY.

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