Possible to implement a manual increment with just simple SQL INSERT?

Question

I have a primary key that I don\'t want to auto increment (for various reasons) and so I\'m looking for a way to simply increment that field when I INSERT. By simply, I mean

Answer 1

If you're doing it in a trigger, you could make sure it's an "INSTEAD OF" trigger and do it in a couple of statements:

DECLARE @next INT
SET @next = (SELECT (MAX(id) + 1) FROM Table1)

INSERT INTO Table1
VALUES (@next, inserted.datablob)

The only thing you'd have to be careful about is concurrency - if two rows are inserted at the same time, they could attempt to use the same value for @next, causing a conflict.

Does this accomplish what you want?