[Database class] Entering data into database

[Paul S. Wang]

Dear DB class,

It is important to remember that when forming a query
in PHP,  we must make sure that all the values are valid
for the table attributes.  For example, a qty attribute must have
a  non-zero positive integer as value.  A zip code must have
5 base-10 digits, etc.

This is especially important when user input is involved in
forming the query.

Just wanted everyone to keep this in mind when doing the term
project.

Paul
-- 
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 Paul S. Wang (王士弘)                      Email: pwang at cs.kent.edu            
 Dept. of Computer Science, Kent State U.   Tel: (330) 672-9051
 Kent, Ohio, USA 44242-0001                 http://www.cs.kent.edu/~pwang/ 
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