An example is the relational model in which all data is represented by mathematical relations (or, to be precise, a slightly generalized version thereof). It furthermore defines a set of specific constraints (candidate keys[?], foreign keys) and a general language for specifying constraints (first-order logic), and for manipulations and querying the data the relational algebra, tuple calculus and domain calculus are introduced.
Other examples are the Functional Data Model[?], the Entity-Relationship Model[?] and the Object Role Model[?] although these usually only describe a small subset of the aspects described above.
Search Encyclopedia
|
Featured Article
|