联接查询等效于Not IN子句（SQL Server 2008）

Question

I have a query with a not in clause like this:

select * 
FROM COMPANY c 
where c.company_id not In (SELECT SenderId 
                            FROM CrossRef) 
  and c.id not in (select company_id 
                    FROM USER)

I am wondering if there is a way to re-write that query using a left join in SQL Server 2008.

I tried the following one but it's not giving the correct result

select c.id, c.company_id 
from COMPANY c 
left join CrossRef cr on c.company_id != cr.senderid, COMPANY c1 
left join USER u on c1.id != u.company_id

Answer 1

SELECT *
FROM Company C
LEFT JOIN CrossRef R ON R.SenderID = C.CompanyID
LEFT JOIN [User] U ON U.company_id = C.id
WHERE R.SenderID IS NULL
  AND U.company_id IS NULL