To find non-matching rows between two tables A & B whose PK is a composite key of three cols, I use the query -

SELECT DISTINCT A.*
FROM Table1 A
INNER JOIN Table2 B
ON A.[Col1] <> B.[Col1]
AND A.[Col2] <> B.[Col2]
AND A.[col3] <> B.[col3]

I need the non-matching rows of Table A only. My question is - Is the above query correct? Any better way to find non-matching rows of A.

Thanks

Your query will not work.

1)
Select *
from tableA ta
where NOT EXISTS
(select null
from tableB tb
where ta.a = tb.a AND
ta.b = tb.b AND
ta.c = tb.c)

2)
Select *
from tableA ta
LEFT OUTER JOIN
tableB tb ON
ta.a = tb.a AND
ta.b = tb.b AND
ta.c = tb.c
WHERE tb.a IS NULL

Thanks. I shall use option 2.