About Unique Constraint

[srs_grp]

Hello,
I want to check uniqueness of id at the time of entry only.And I want to give message to the user at that time only.How to do this?

[stephen84s]

Either you generate the Id and assign it to the user yourself using an autoincrement or a UUID feature, but if you want the user to select his own ID you will have to perform a check in your records (database or files) to check if the ID has already been chosen by someone else.

[srs_grp]

Either you generate the Id and assign it to the user yourself using an autoincrement or a UUID feature, but if you want the user to select his own ID you will have to perform a check in your records (database or files) to check if the ID has already been chosen by someone else.

yes.. but the problem is where should I perform this check,so that I can immediately inform user abt constraint violation.

[stephen84s]

That depends, what are you working on right now, what type of application is it ? A web page, Swing form ? You want specific answers but you haven't yet given details specific to your application.