| Περίληψη: | This chapter focuses on the basic concepts of the Relational Model, which is the most common and widely used data management model. The Relational Model is based on organizing data in tables (or relations) which are linked with each other through common attributes. The purpose of the chapter is that the reader understands the philosophy of organizing data and the basic elements of the model, such as the tables, relationships and keys. The Entity-Relationship Diagram is also presented as a tool for capturing the informational needs of a data base, as well as the step-by-step process of designing a data base. Reference is also made to issues of normalization, data redundancy and integrity.
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