March 2003
Beginner
672 pages
14h
English
book
Database Design for Mere Mortals™: A Hands-On Guide to Relational Database Design, Second Edition
by Michael J. Hernandez
Content preview from Database Design for Mere Mortals™: A Hands-On Guide to Relational Database Design, Second Edition
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Establishing Keys for Each Table
Your next task is to establish keys for each table in the database. There are four main types of keys: candidate, primary, foreign, and non-keys. A key's type determines its function within the table.
Candidate Keys
The first type of key you establish for a table is the candidate key, which is a field or set of fields that uniquely identifies a single instance of the table's subject. Each table must have at least one candidate key. You'll eventually examine the table's pool of available candidate keys and designate one of them as the official primary key for the table.
Before you can designate a field as a candidate key, you must make certain it complies with all of the Elements of a Candidate Key. These ...
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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.