title: Can I make a SQL Server 2005 Table Column accept only letters and numbers?
body: <p>When we have a column that will store a username that will only accept letters and numbers we always do validation on this input field using javascript or even server validation from code .. but i want to know if is there any way that can allow me make this validation on the Table column itself even some one try to enter data from any place it don't accept and throw exception  ?</p>