SQL 2012 :: Populate Int Column With A Sequence Of Numbers But Sorted By Another Field

The following works just fine. The table tmpMHPCLMDET does have a column ADMTDT ( varchar(8) ).

While I am adding the sequence of numbers I like it to be sorted based on ADMTDT column.

What that means is the row with the earliest ( smallest ) ADMTDT will get 1 and the next 2 and so on.

Declare @ID int
If Exists ( Select c.name from sys.columns c where object_id = object_id('tmpMHPCLMDET') and C.name = 'ServiceLineID' )
Begin
--Adding a sequence of numbers to the ServiceLineID column.
SET @id = 0
UPDATE tmpMHPCLMDET
SET @id = ServiceLineID = @id + 1;
End;