Understanding SQL & Java Together: A Guide to SQLJ, JDBC, and Related Technologies
A comprehensive guide to how the marriage of SQL and Java is forging a new era in object-oriented databases.
TABLE OF CONTENTS Understanding SQL & Java Together: A Guide to SQLJ, JDBC, and Related Technologies
7.10: SQL Object Model
7.10 SQL Object Model
If you've been around the computer software business long enough, you've heard lots of buzzwords and phrases. One of the hottest such phrases in recent years is "data model." Regrettably, because of the confusion that it often causes, the phrase applies to a rather wide variety of concepts, ranging from a description of the data elements required by a specific application to techniques and methodologies used to design very large systems. In the context of database systems, the phrase is often intended to identify the underlying concepts supported by those systems.
7.10.1 Why Does SQL have an Object Model?
In 1989, we heard Dr. E. F. Codd tell a seminar that object-oriented approaches are not needed in the database environment. He suggested that they're OK for programming languages, which don't "have the power to express complex ideas," but "the relational model is more than adequate for data storage." Dr. Codd went on to acknowledge that the relational model is not necessarily appropriate for " all masses of data: for example, image data and voice- or finger-printing, where the sequence of bits is important." Codd's rationale for this rejection of a need for object orientation in the database environment was straightforward: The relational model is a true model because it is based on a solid mathematical foundation and its principles are provable mathematically. By contrast, there are many different "approaches" that are called object models, and none of them have mathematical foundations. Their principles are...
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