June 2010
Intermediate to advanced
266 pages
5h 55m
English
Content preview from Patterns of Data ModelingBecome 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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Chapter 11
Identity
Identity is the property that distinguishes an entity from all others. In concept, an entity has intrinsic identity apart from how the entity may happen to be implemented. Users must be able to find data in a database or the database is compromised.
11.1 Intrinsic Identity
Intrinsic identity is the ability to find data with fields that have meaning. Starting from outside a database, a user specifies real-world fields to find one or more entities and then navigates the database to find the desired data. Intrinsic identity has no bearing on how identity is implemented. Rather intrinsic identity provides a way for logically finding entities when searching a database.
11.1.1 Candidate Keys
Candidate keys provide one aspect of ...
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