I am going to take a shot in the dark as to what you want. It seems that most your "key" is made up of values already in the table. This is where you could use a computed column. It also seems from earlier that you have some poor decisions in your table structure. It seems like you have material and classification as a single field. This is what is known as attribute splitting. Each column should contain one and only one value. Don't make things harder for yourself. Also you want to store the year. I would not do this as an int column. Instead make it datetime and then you can return only the year portion if you want.

Here is my take on how you could do this. You may have to

IF OBJECT_ID('TempDB..#Haulers','U') IS NOT NULL

drop table #Haulers

create table #Haulers

(

HaulerID int identity primary key,

Asset char(1),

Material char(1),

Classification char(1),

DateCreated datetime not null default getdate(),

PermitNumber as right(replicate('0', 5) + cast(HaulerID as varchar(5)),5) + '-' + Asset + Material + Classification + cast(year(DateCreated) as char(4)) PERSISTED

)

insert #Haulers

select 'A', 'M', 'C', GETDATE() union all

select 'T', 'U', 'X', GETDATE()

select * from #Haulers

Please notice the PERSISTED keyword at the end of the column definition. This is important so you can add an index to this column. You can read more about persisted columns here. http://msdn.microsoft.com/en-us/library/ms191250%28v=sql.105%29.aspx