Author Question: Describe primary and foreign keys. How do they differ? When and how they are needed? What will be ... (Read 47 times)

cartlidgeashley · **on:** Jul 7, 2018

Describe primary and foreign keys. How do they differ? When and how they are needed?

What will be an ideal response?

Question 2

Telecommuting is facilitated by all of the following except:

A) privacy laws.
B) low costs for personal computing products.
C) Internet connectivity.
D) software to facilitate remote collaboration.

Ptupou85 · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

A primary key is an attribute or a set of attributes whose values uniquely identify a row. The relationship between entities in different tables is established through foreign keys. The foreign key is an attribute in one table, the value of which must match the value of a primary or an alternate key in another table. Unlike primary keys, foreign keys are not required and do not, necessarily, identify a row uniquely. Like primary keys, a foreign key can be composite, consisting of more than one attribute.

Answer to Question 2

A