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Abstraction in sql are views, done with left joins (rules in prolog). It doesn't seem like much, but that's the beauty of of it, you only need one concept and t
by unono 13y ago
Abstraction in sql are views, done with left joins (rules in prolog). It doesn't seem like much, but that's the beauty of of it, you only need one concept and that's all you need. Contrast that with other languages where you have hundreds of little functions.
- tome 13y agoNot all abstractions are relations though. In SQL can you abstract the functionality of "take a relation with one int column, one string column, one double column, sum the int column, group by the string column and average the double column"? Do views support the notion of primary keys and foreign keys? I wouldn't be able to program in SQL without the former, and the latter would also be useful.