How to get Identity of new records INSERTED into table with INSTEAD OF trigger

问题

I am using an INSTEAD OF insert trigger on a table to set an incrementing version number on the row and also copy the row to a 2nd history/audit table.
The rows are inserted to both tables without a problem.
However, I am having trouble returning the new identity from the 1st table back to the user.

Schema

CREATE TABLE Table1
(
   id INT IDENTITY(1,1) PRIMARY KEY,
   name VARCHAR(250) NOT NULL UNIQUE,
   rowVersion INT NOT NULL
)

CREATE TABLE Table1History
(
   id INT NOT NULL,
   name VARCHAR(250) NOT NULL,
   rowVersion INT NOT NULL
)   

CREATE TRIGGER TRG_INS_Table1
ON Table1
INSTEAD OF INSERT
AS
    DECLARE @OutputTbl TABLE (id INT, name VARCHAR(250))
BEGIN
--make the insert
INSERT INTO Table1 (name, rowVersion)
    OUTPUT INSERTED.id, INSERTED.name INTO @OutputTbl(id, name)
    SELECT i.name, 1
    FROM INSERTED i
--copy into history table
INSERT INTO Table1History (id, name, rowVersion)
    SELECT t.ID, i.name, 1
    FROM INSERTED i
    JOIN @OutputTbl t on i.name = t.name
END

CREATE TRIGGER TRG_UPD_Table1
ON Table1
INSTEAD OF UPDATE
AS
BEGIN
--make the update
UPDATE Table1
    SET name = i.name,
        rowVersion = (SELECT d.rowVersion + 1 FROM DELETED d WHERE d.id = i.id)
    FROM INSERTED i
    WHERE Table1.id = i.id
--copy into history table
INSERT INTO Table1History (id, name, rowVersion)
    SELECT i.id ,i.name, (SELECT d.rowVersion + 1 FROM DELETED d WHERE d.id = i.id)
    FROM INSERTED i
END

Joining on the name column in the insert trigger is not ideal, but it needs to handle multiple inserts at once.
eg INSERT INTO Table1 (name) VALUES('xxx'),('yyy')

Attempted Solutions

When doing an insert, SCOPE_IDENTITY is NULL.

INSERT INTO Table1(name)
VALUES('xxx')
SELECT SCOPE_IDENTITY() 

or 

INSERT INTO Table1(name)
VALUES('xxx')
RETURN SCOPE_IDENTITY()

I've also tried using OUTPUT - which returns 0:

DECLARE @IdentityOutput TABLE (id INT)
INSERT INTO Table1(name)
OUTPUT INSERTED.id INTO @IdentityOutput
VALUES('xxx')
SELECT id FROM @IdentityOutput

The rows are inserted fine and have IDs, but I cannot access them unless I use the below - which seems hacky:

INSERT INTO Table1(name)
VALUES('xxx')
SELECT id from Table1 WHERE name = 'xxx' 

What is the proper way to get the new ID??

---

Solution

Impossible! You can't reliably return the identity when doing an INSERT on a table that has an INSTEAD OF trigger. Sidux's answer below is a good workaround for my situation (replace INSTEAD OF trigger with AFTER trigger and added DEFAULT columns).

回答1:

CREATE TABLE Table1
(
   id INT IDENTITY(1,1) PRIMARY KEY,
   name VARCHAR(250) NOT NULL UNIQUE,
   rowVersion INT NOT NULL
)
GO
CREATE TABLE Table1History
(
   id INT NOT NULL,
   name VARCHAR(250) NOT NULL,
   rowVersion INT NOT NULL
)   
GO
CREATE TRIGGER TRG_INS_Table1
ON Table1
INSTEAD OF INSERT
AS
    DECLARE @OutputTbl TABLE (id INT, name VARCHAR(250))
BEGIN
--make the insert
INSERT INTO Table1 (name, rowVersion)
    SELECT i.name, 1
    FROM INSERTED i
END
GO
CREATE TRIGGER TRG_UPD_Table1
ON Table1
INSTEAD OF UPDATE
AS
BEGIN
--make the update
UPDATE Table1
    SET name = i.name,
        rowVersion = (SELECT d.rowVersion + 1 FROM DELETED d WHERE d.id = i.id)
    FROM INSERTED i
    WHERE Table1.id = i.id
END
GO
CREATE TRIGGER TRG_AFT_INS_Table1
ON Table1
AFTER INSERT, UPDATE
AS

BEGIN

INSERT INTO Table1History (id, name, rowVersion)

    SELECT i.ID, i.name, i.rowversion
    FROM INSERTED i

END
GO

INSERT INTO Table1 (name) VALUES('xxx'),('yyy')

SELECT * FROM Table1History
-----------------------------------------------
id  name    rowVersion
2   yyy 1
1   xxx 1
-----------------------------------------------

UPDATE Table1 SET name = 'xxx1' WHERE id  = 1;

SELECT * FROM Table1History
-----------------------------------------------
id  name    rowVersion
2   yyy 1
1   xxx 1
1   xxx1    2
-----------------------------------------------

Basically you do not need TRG_INS_Table1 trigger, you can just use DEFAULT value = 1 for column and that's it. Also if you use DATETIME column instead of rowversion, you can just insert the state of INSERTED table to the history with the GETDATE() value. In that case you can order by Dtime column DESC and you have history.

来源：https://stackoverflow.com/questions/29116093/how-to-get-identity-of-new-records-inserted-into-table-with-instead-of-trigger