Tuesday, December 20, 2016

what is candidate keys? (C++)

A candidate key is a minimal set of attribute that uniquely identifies an object or link.

A class or association may have one or more candidate keys,each of which may have different combinations and numbers of attributes.

Candidate key is a term commonly used within the database community . however, candidate key is really not a database concept; candidate key is a logical concept. Each candidate key constraints the instances in class or the multiplicity of an association.  Most programming languages lack the notation of a candidate key. A candidate key is defined in an object model with braces.

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