Dana Halsey is chair of the Purebred Marmoset Society,which maintains a database of registered purebred marmosets and their breeding history.One table will store the name,birth date,and other characteristics of all of the marmosets that have been registered.Each marmoset is uniquely identified by a registration number.A second table will contain data that link each marmoset to its male and female parents by means of their registration numbers.The primary key in the second table is:
A) name
B) birth date
C) a combination of primary keys in the first table
D) the same as the primary key in the first table

Question

Quizplus · Accepted Answer

The second table needs to have a unique identifier for each marmoset, and this identifier should be the registration number that is already used as the primary key in the first table. However, the second table also needs to link each marmoset to its parents, and this can be accomplished by including the registration numbers of the parents as foreign keys in the second table. The combination of these foreign keys can be used as the primary key in the second table, as each marmoset will have a unique combination of parents.

Dana Halsey Is Chair of the Purebred Marmoset Society,which Maintains