Can a sql server table have two identity columns?

Question

I need to have one column as the primary key and another to auto increment an order number field. Is this possible?

EDIT: I think I\'ll just use a composite number a

Answer 1

I've just created a code that will allow you inserting two identities on the same table. let me share it with you in case it helps:

create trigger UpdateSecondTableIdentity
On TableName For INSERT
as
update TableName
set SecondIdentityColumn = 1000000+@@IDENTITY
where ForstId = @@IDENTITY;

Thanks,

Answer 2

CREATE TABLE [dbo].[Foo](
    [FooId] [int] IDENTITY(1,1) NOT NULL,
    [BarId] [int] IDENTITY(1,1) NOT NULL
)

returns

Msg 2744, Level 16, State 2, Line 1
Multiple identity columns specified for table 'Foo'. Only one identity column per table is allowed.

So, no, you can't have two identity columns. You can of course make the primary key not auto increment (identity).

Edit: msdn:CREATE TABLE (Transact-SQL) and CREATE TABLE (SQL Server 2000):

Only one identity column can be created per table.

Answer 3

A workaround would be to create an INSERT Trigger that increments a counter.

So I have a table that has one identity col : applicationstatusid. its also the primary key. I want to auto increment another col: applicationnumber

So this is the trigger I write.

 create trigger [applicationstatus_insert] on [ApplicationStatus] after insert as 
       update [Applicationstatus] 
       set [Applicationstatus].applicationnumber =(applicationstatusid+ 4000000) 
       from [Applicationstatus] 
       inner join inserted on [applicationstatus].applicationstatusid = inserted.applicationstatusid

Answer 4

The primary key doesn't need to be an identity column.

You can't have two Identity columns.

You could get something close to what you want with a trigger...

Answer 5

in sql server it's not possible to have more than one column as identity.

Answer 6

Add one identity column and then add a computed column whose formula is the name of the identity column

Now both will increment at the same time