I have a .NET 2.0 guestbook like application that untilizes a std "DetailsView" control webpage ( ) .
User enter's his or her name, email address and employee# and clicks a button labelled "INSERT"
to enter "sign-up" data record ( one at a time) into the SQL Server.
THe only code is one simple "INSERT INTO TABLE .......... firstname,lastname, etc "
The problem here is the user can possiblily add themselves more then once to the guest list.
How do the pro's prevent duplicate records entering in SQL server.
Is there something simple that can be done to prevents ( a key on database etc) .
What do I have to do here to prevent possible duplicate records?