Insert new record into autonumbered table, and then use the autonumber in another table - sql

Question

I'm writing a stored procedure to insert data from a form into two tables. One table has an autonumbered identity field. I need to insert the data into that table, find the newly created autonumber, and use that number to insert data into another table. So, to boil it down, I have a one-to-many link between the two tables and I need to make sure the identity field gets inserted.
Is this code the best way to do something like this, or am I missing something obvious?
CREATE PROCEDURE [dbo].[sp_Insert_CRT]
(
#TRACKING_ID int,
#CUST_NUM int,
#TRACKING_ITEM_ID int,
#STATEMENT_NUM nvarchar (200) = null,
#AMOUNT numeric (15, 2),
#BBL_ADJUSTED int = NULL,
#PAID_VS_BILLED int = NULL,
#ADJUSTMENT_TYPE int = NULL,
#ENTERED_BY nvarchar (10) = NULL,
#ENTERED_DATE date = NULL,
#AA_STATUS int = NULL
)
AS
BEGIN
-- Insert data into CRT_Main, where Tracking_ID is an autonumber field
INSERT into tbl_CRT_Main
(
-- TRACKING_ID
CUST_NUM
,TRACKING_ITEM_ID
,STATEMENT_NUM
,AMOUNT
)
VALUES
(
-- #TRACKING_ID
#CUST_NUM
,#TRACKING_ITEM_ID
,#STATEMENT_NUM
,#AMOUNT
)
-- Find the newly generated autonumber, and use it in another table
BEGIN TRANSACTION
DECLARE #TrackID int;
SELECT #TrackID = coalesce((select max(TRACKING_ID) from tbl_CRT_Main), 1)
COMMIT
INSERT into tbl_CRT_Admin_Adjustment
(
TRACKING_ID
,BBL_ADJUSTED
,PAID_VS_BILLED
,[ADJUSTMENT_TYPE]
,[ENTERED_BY]
,[ENTERED_DATE]
,AA_STATUS
)
VALUES
(
#TrackID
,#BBL_ADJUSTED
,#PAID_VS_BILLED
,#ADJUSTMENT_TYPE
,#ENTERED_BY
,#ENTERED_DATE
,#AA_STATUS
)
END

Answer 1

SELECT #TrackID = coalesce((select max(TRACKING_ID) from tbl_CRT_Main), 1)
No, don't do this. This will get you the maximum value of TRACKING_ID yes, but that doesn't mean that's the value that was created for your INSERT. If multiple INSERT statements were being run by different connections then very likely you would get the wrong value.
Instead, use SCOPE_IDENTITY to get the value:
SET #TrackID = SCOPE_IDENTITY();
Also, there is no need to wrap the above in an explicit transaction like you have with your SELECT MAX(). Instead, most likely, the entire batch in the procedure should be inside it's own explicit transaction, with a TRY...CATCH so that you can ROLLBACK the whole batch in the event of an error.