Getting Started with SQL and Databases

Аннотация

In the distant past, data was managed by computers in all sorts of ways, and there was no one way to do this. There still isn’t, which isn’t a bad thing, because not all data can be handled the same way. There is, however, a large body of data which can be handled in a common way, and the early 1970s saw the development of a set of mathematical principles in the relational model.