What columns can be used in OUTPUT INTO clause?

Question

I\'m trying to build a mapping table to associate the IDs of new rows in a table with those that they\'re copied from. The OUTPUT INTO clause seems perfect for that, but it does

Answer 1

I think I found a solution to this problem, it sadly involves a temporary table, but at least it'll prevent the creation of a dreaded cursor :) What you need to do is add an extra column to the table you're duplicating records from and give it a 'uniqueidentifer' type.

then declare a temporary table:

DECLARE @tmptable TABLE (uniqueid uniqueidentifier, original_id int, new_id int)

insert the the data into your temp table like this:

insert into @tmptable
(uniqueid,original_id,new_id)
select NewId(),id,0 from OriginalTable

the go ahead and do the real insert into the original table:

insert into OriginalTable
(uniqueid)
select uniqueid from @tmptable

Now to add the newly created identity values to your temp table:

update @tmptable
set new_id = o.id
from OriginalTable o inner join @tmptable tmp on tmp.uniqueid = o.uniqueid

Now you have a lookup table that holds the new id and original id in one record, for your using pleasure :)

I hope this helps somebody...