November 2001
Intermediate to advanced
504 pages
10h 18m
English
Content preview from Developing Applications with Java™ and UMLBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Key Structures and Normalization
You might have seen some column names such as customerId and productId in previous tables. These columns relate to keys and normalization. Every persistent object in the system must be uniquely identified; the nature of object design and implementation frees us, somewhat, from having to worry about object uniqueness. When an object of a given class is created, it is assigned a unique ID for its lifetime; this is done internally in the language subsystem. However, unique IDs are not assigned when the object is persisted to, for example, Microsoft SQL Server or Oracle. When making the transition from the object view to the relational view, we need to consider the primary identifiers, or keys, that will make every ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.