FULL OUTER JOIN concept

I have 3 tables with some values.Some of the ID's are present in Table A,Some in Table B and other in Table C.I just want to know,what are the values present in one table are not present in another table.

SELECT A.ID,B.ID,C.ID

FROM A FULL OUTER JOIN B ON A.ID=B.ID

             FULL OUTER JOIN C ON A.ID=C.ID  OR B.ID=C.ID

ORDER BY A.ID,B.ID,C.ID                                                                                                                                                                                                                                     





It is easy only when you have understanding of JOINS concept in SQL.