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'm running into EXACTLY the same problem as you are, I feel your pain... As far as I've been able to find out there's no way to use the from_table_name prefix with an INSERT statement. I'm sure there's a viable technical reason for this, and I'd love to know exactly what it is.

Ok, found it, here's a forum post on why it doesn't work: MSDN forums

Answer 2

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...

Answer 3

I've verified that the problem is that you can only use INSERTED columns. The documentation seems to indicate that you can use from_table_name, but I can't seem to get it to work (The multi-part identifier "m.ContentID" could not be bound.):

TRUNCATE TABLE main

SELECT *
FROM incoming

SELECT *
FROM main

DECLARE @Missing TABLE (ContentID INT PRIMARY KEY)
INSERT INTO @Missing(ContentID) 
SELECT incoming.ContentID
FROM incoming
LEFT JOIN main
    ON main.ContentID = incoming.ContentID
WHERE main.ContentID IS NULL

SELECT *
FROM @Missing

DECLARE @Inserted TABLE (ContentID INT PRIMARY KEY, [Content] varchar(50))
INSERT INTO main(ContentID, [Content]) 
OUTPUT INSERTED.ContentID /* incoming doesn't work, m doesn't work */, INSERTED.[Content] INTO @Inserted (ContentID, [Content])
SELECT incoming.ContentID, incoming.[Content] 
FROM incoming
INNER JOIN @Missing AS m
    ON m.ContentID = incoming.ContentID

SELECT *
FROM @Inserted

SELECT *
FROM incoming

SELECT *
FROM main

Apparently the from_table_name prefix is only allowed on DELETE or UPDATE (or MERGE in 2008) - I'm not sure why:

• from_table_name

Is a column prefix that specifies a table included in the FROM clause of a DELETE or UPDATE statement that is used to specify the rows to update or delete.

If the table being modified is also specified in the FROM clause, any reference to columns in that table must be qualified with the INSERTED or DELETED prefix.

Answer 4

You can do this with a MERGE in Sql Server 2008. Example code below:

--drop table A
create table A (a int primary key identity(1, 1))
insert into A default values
insert into A default values

delete from A where a>=3

-- insert two values into A and get the new primary keys
MERGE a USING (SELECT a FROM A) AS B(a)
ON (1 = 0) -- ignore the values, NOT MATCHED will always be true
WHEN NOT MATCHED THEN INSERT DEFAULT VALUES -- always insert here for this example
OUTPUT $action, inserted.*, deleted.*, B.a; -- show the new primary key and source data

Result is

INSERT, 3, NULL, 1
INSERT, 4, NULL, 2

i.e. for each row the new primary key (3, 4) and the old one (1, 2). Creating a table called e.g. #OUTPUT and adding " INTO #OUTPUT;" at the end of the OUTPUT clause would save the records.

Answer 5

(MS) If the table being modified is also specified in the FROM clause, any reference to columns in that table must be qualified with the INSERTED or DELETED prefix.

In your example, you can't use cglobal table in the OUTPUT unless it's INSERTED.column_name or DELETED.column_name:

INSERT INTO Private.Content 
    (Tag) 
    OUTPUT cglobal.ContentID, INSERTED.ContentID 
    INTO @Inserted (SrcContentID, TgtContentID)
SELECT Tag
    FROM Private.Content AS cglobal
    INNER JOIN @Missing AS m ON cglobal.ContentID = m.SrcContentID

What worked for me was a simple alias table, like this:

INSERT INTO con1 
    (Tag) 
    OUTPUT **con2**.ContentID, INSERTED.ContentID 
    INTO @Inserted (SrcContentID, TgtContentID)
SELECT Tag
    FROM Private.Content con1
    **INNER JOIN Private.Content con2 ON con1.id=con2.id**
    INNER JOIN @Missing AS m ON con1.ContentID = m.SrcContentID