如何为多个用户的每个数据库条目创建唯一ID

I am working on a c# program that will be used by 20 to 60 users concurrently. The users will input information into various text fields and select from combo boxes and then save the information to a shared database. My question is how can I create a unique ID for each entry to the database so that they can later do a search by the ID? By preference I would like the ID to be less than 8 characters or digits. The database is designed in SQL Server 2012 Express. I am working on a c# program that will be used