Constraints question

[Dennis Fleming]

RBWin

I have provided my users with a command file to add system constraints to
columns where there were none and should have been some. i.e., 

ALTER TABLE 'parts' ALTER COLUMN 'pr_unitp' CURRENCY NOT NULL

If this command file is run more than once, will constraints be duplicated?
For example, where an index is created. And what is the best/easiest way to
avoid this? 

TIA,

Dennis
*****
Dennis Fleming
IISCO
http://www.TheBestCMMS.com