Question

define primary key candidate key alternate key foreign key table record field Database​

Answer 1

A DBMS key is an attribute or set of an attribute which helps you to identify a row(tuple) in a relation(table). They allow you to find the relation between two tables. Keys help you uniquely5 identify a row in a table by a combination of one or more columns in that table.

Example:

Employee ID FirstName LastName

11 Andrew Johnson

22 Tom Wood

33 Alex Hale

In the above-given example, employee ID is a primary key because it uniquely identifies an employee record. In this table, no other employee can have the same employee ID.