sql - Converting sub query

Question

How can I convert this subquery to join query or something more simple like with?

SELECT *
FROM ViewBuy99
WHERE Id NOT IN (
        SELECT Id
        FROM Buy99
        )

INSERT INTO Buy99
SELECT *
FROM ViewBuy99
WHERE Id NOT IN (
        SELECT Id
        FROM Buy99
        )

Answer 1

You can express this using JOIN as:

insert into Buy99
    select vb.*
    from ViewBuy99 vb left join
         Buy99 b
         on b.id = vb.id
    where b.id is null;

However, I would recommend NOT EXISTS:

insert into Buy99
    select vb.*
    from ViewBuy99 vb 
    where not exists (select 1 
                      from Buy99 b
                      where b.id = vb.id
                     );