By C. J. Date
Type inheritance is that phenomenon in line with which we will be able to say, for instance, that each sq. is usually a rectangle, and so homes that practice to rectangles ordinarily practice to squares specifically. In different phrases, squares are a subtype of rectangles, and rectangles are a supertype of squares. spotting and appearing upon such subtype / supertype relationships offers a number of merits: definitely it could possibly assist in information modeling, and it could additionally offer for code reuse in functions. For those purposes, many languages, together with the traditional database language SQL, have lengthy supported such relationships. despite the fact that, there doesn’t appear to be any consensus in the neighborhood at huge on a proper, rigorous, and summary version of inheritance. This booklet proposes this kind of version, one who enjoys numerous benefits over different methods, no longer the least of which it really is that it’s totally suitable with the well-known relational version of data.
Topics the version covers include:
- Both unmarried and a number of inheritance
- Scalar, tuple, and relation inheritance
- Type lattices and union and intersection types
- Polymorphism and substitutability
- Compile time and run time binding
All of those subject matters are defined intimately within the ebook, with various illustrative examples, workouts, and solutions. The publication additionally discusses a number of substitute methods. specifically, it incorporates a unique dialogue and research of inheritance as supported within the SQL standard.