Update table row with inserted identity ID - sql

Question

I have the following query:
INSERT INTO dbo.Products
( Code ,
ProducerCode ,
CustomerId ,
EanCode ,
ChangedDateTime ,
ChangedById ,
Deleted
)
SELECT Code ,
ProducerCode ,
CustomerId ,
EanCode ,
GETDATE(),
GETDATE(),
0
FROM dbo.BulkProducts
WHERE ProductId is NULL AND BulkProducts.BulkId = #BulkId
The Products table has an IDENTITY ID column, which is assigned automatically on insert. What I want to achieve is, after the insertion in Products, have the assigned ID of the product in the row from BulkProducts. I have read a bit about##IDENTITY, IDENT_CURRENT and SCOPE_IDENTITY but I cannot seem to get it to work for my example. Any help appreciated. I am using SQL Server 2012.

Answer 1

You can achieve it using Output clause, like this -
DECLARE #OutProduct TABLE
(
ProductID INT,
Code INT
)
INSERT INTO dbo.Products
( Code ,
ProducerCode ,
CustomerId ,
EanCode ,
ChangedDateTime ,
ChangedById ,
Deleted
)
OUTPUT INSERTED.ID, INSERTED.Code INTO #OutProduct (ProductID, Code)
SELECT Code ,
ProducerCode ,
CustomerId ,
EanCode ,
GETDATE(),
GETDATE(),
0
FROM dbo.BulkProducts
WHERE ProductId is NULL AND BulkProducts.BulkId = #BulkId
So Now all your inserted data are in #OutProduct table. Now you can update your BulkProducts table using that temp table like below.
UPDATE bprod
SET productID = tmp.ProductID
FROM BulkProducts bprod
INNER JOIN #OutProduct tmp
ON bprod.Code = tmp.Code
WHERE bprod.ProductId is NULL AND bprod.BulkId = #BulkId

Answer 2

Apparently this cannot be solved without a MERGE. The final solution looks like this:
MERGE INTO dbo.Products
USING dbo.BulkProducts AS src
ON 1 = 0 -- Never match
WHEN NOT MATCHED THEN
INSERT(EanCode, ChangedDateTime, ChangedById, Deleted)
VALUES(src.EanCode, GETDATE(), GETDATE(), 0)
OUTPUT
inserted.Id,
src.Id
INTO #OutProduct;
And like this, my #OutProduct table contains tuples of BulkProductId and ProductId which I can then use to update my BulkProducts table.