It states :
It took me a minute to find a good example to illustrate the difference between the two, but with a trigger I created the following example:
@@IDENTITY, SCOPE_IDENTITY, and IDENT_CURRENT are similar functions because they all return the last value inserted into the IDENTITY column of a table.
@@IDENTITY and SCOPE_IDENTITY return the last identity value generated in any table in the current session. However, SCOPE_IDENTITY returns the value only within the current scope; @@IDENTITY is not limited to a specific scope.
CREATE TABLE tst
( a int identity(1,1), s varchar(10))
CREATE TABLE tst2
( a int identity(1000,1), s varchar(10))
CREATE TRIGGER dbo.trgTst
AS INSERT tst2 SELECT inserted.s FROM inserted
INSERT tst VALUES('a')
@@IDENTITY AS [@@IDENTITY],
SCOPE_IDENTITY() AS [SCOPE_IDENTITY()]
DROP TABLE tst2
DROP TABLE tst
SCOPE_IDENTITY() will give you the value of tst.$IDENTITY, ignoring the identity value that is generated for table tst2 with the trigger after the insert into tst. @@IDENTITY will give you that value from tst2.$IDENTITY.
So the function we actually need in our case is not @@IDENTITY but SCOPE_IDENTITY().