>I have a database with several tables, the tables have principal indexes, but when I want to add a record with a key value that exist but is deleted,i can't because the key must be unique.How can I solve this problem ?
Easy. Don't reuse keys. By definition, a PK is unique for each row in the table. When you delete a record, the record still exists. There is a more complete discussion on my web site.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer