Re: constraint question

"D. Duccini" wrote:
> 
> what language are you using? 

Im using php/web interface to enter the data - I'ts easy enough to
restrict whats entered that way using ereg etc- but occasionaly I find
it quicker/easier to just do stuff by isql and so wanted to try and
restrict it at the database level -
it's not absolutely neccessary - I as more interested in knowing how to
do it.


 might be easier to perform the check
> programatically and provide thoughtful feedback at that level as opposed
> to a db constraint
> 
> just suggestion
> 
> On Mon, 1 Jan 2001 mwaples@optusnet.com.au wrote:
> 
> > I have table users with a varchar field user_name,
> > Id like to restrict this to just alphanumeric characters
> > can I do this with a check constraint ?
> > or do I need to use a tigger and function ?
> >
> > I've read the docs but can't seem to get it right - Im sure its fairly
> > simple and Id like to use it on a number of fields in a number of tables