Modify an existing column for identification

Question

Possible duplicate:
How to change a non-identity program column by one?

I want to set the column as an identifier since I already created this column in the table.

What syntax do I need? ALTER ...?

Answer 1

You cannot add an identifier to an existing column; you must create a new column.

Answer 2

With table test

create table Test(ID int)

You can do it

exec sp_rename 'dbo.Test', 'tmp_Test', 'OBJECT'
go

create table dbo.Test(
  ID int not null identity
)
go

set identity_insert dbo.Test on
go

insert into dbo.Test(ID) select ID from dbo.tmp_Test
go

set identity_insert dbo.Test off
go

drop table dbo.tmp_Test
go

Answer 3

SMSS → . → - > - > .

Answer 4

SQL, :

ALTER TABLE <TableName> ADD CONSTRAINT PK_<TableName> PRIMARYKEY(Column)