SQL命令插入的值将大于1然后大于最大值

Question

I need that the minimal id will be 0(zero).

I tried something like this:

INSERT INTO users(id, name) 
VALUES ( (SELECT MAX(id) FROM users) + 1 , 'andrey6' )

But I have a problem when the "users" table is empty, I just cant figure out how to keep the minimal value to be 0.

Answer 1

Does this do what you want:

INSERT INTO users(id, name) 
VALUES ( (SELECT IFNULL(MAX(id) + 1,0) FROM users) , 'andrey6' )

?

Answer 2

You could just use COALESCE like so:

INSERT INTO users(id, name) 
VALUES ( (SELECT COALESCE(MAX(id), 0) FROM users) + 1 , 'andrey6' )