An Extended Entity-Relationship Model

1. Front Matter

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2. Introduction

   Pages 1-4

3. Structure of data and entities

   Pages 5-34

4. Extended Entity-Relationship calculus

   Pages 35-76

5. PROLOG implementation

   Pages 77-98

6. Formal semantics of SQL

   Pages 99-120

7. Conclusions

   Pages 121-122

8. Back Matter

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This text presents a comprehensive introduction to an extended Entity-Relationship model both on a conceptual and on a formal, mathematicallevel. In addition to the primitives given by the data model the text introduces a language for the formulation of constraints in order to restrict database states to consistent ones. The text explains an implementation of the approach chosen in the logic programing language PROLOG and discusses in this context the computational power of the proposedcalculus. The extended Entity-Relationship calculus is used to define the meaning of the relational query language SQL. A nice feature of the approach is that it becomes possible to prove language properties on a sound mathematical basis.

• Constraint
• Database Design
• Database Query Languauges
• Datenbank-Abfragesprache
• Entity-Relationship Model
• Entity-Relationship-Modell
• Formal Semantics
• SQL
• data model
• logic
• query language

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