Maintaining Data
What is validation?
p. 524 Fig. 10-8
Next
ØProcess of comparing data with a set of rules to find out if data is correct
SAMPLE VALID AND INVALID DATA
10/20/2005
10/13/2005
10/20/2005
10/27/2005
Date Joined
Training Date
Consistency
Check
Valesquez
Last Name
Completeness
Check
$95.25
$39.50
Monthly Fee
Range Check
3rto9
36109
Postal Code
Numeric
Check
Ad33n
Adrian
First Name
Alphabetic Check
Invalid Data
Valid Data
Field Being Checked
Validity
Check
ØReduce data entry errors and enhance data integrity before program writes data on disk