 | GetTextbooks.co.uk Compare Price & Save up to 90% | | |
|
Centenary College of Louisiana - Fall 2012 | ||
Section A | ||
 | Relational Database Design and Implementation : Clearly Explained 3e by Jan L. Harrington Unknown, 440 Pages, Published 2009 ISBN-10: 0-08-088501-2 / 0080885012 ISBN-13: 978-0-08-088501-8 / 9780080885018 As you know, null is a special database value that means “unknown.” Its presence in a database brings special problems during data retrieval. Consider, for example, what happens if you have an employees' relation that contains a column for salary. Assume that the salary is null for some portion o | |