SQL Server - NOT IN

Question

I need to build a query that will show me records that are in Table 1, but that are not in Table 2, based on the make-model-serial number combination.

I know for fac

Answer 1

Use a LEFT JOIN checking the right side for nulls.

SELECT a.Id
FROM TableA a
LEFT JOIN TableB on a.Id = b.Id
WHERE b.Id IS NULL

The above would match up TableA and TableB based on the Id column in each, and then give you the rows where the B side is empty.