Question

What is the function of a primary key in a table? (A.)to uniquely identify each record in the table,(B.)to uniquely identify foreign keys in the table,(C.)to secure table data,(D.)to secure the foreign keys in the table

Answer 1

Answer:

A. To uniquely identify each record in the table

Explanation:

From the list of given options, the option that best describe the primary key is A.

For better understanding of what primary key is all about, I'll make use of the following illustration.

Take for instance; the following relational table fields and records

SN ----- Name ----- Age

1 ------- John ---------15

2------- Peter ------- 17

3 ----- Ruth ----------16

If I've set the primary key of the above table to be SN, this means that no two records can have the same SN because each SN value is unique to every row.

Similarly,if I've set the primary key as Name, then there can only be one occurrence of John, Ruth or Peter because each of these are unique to their rows.