SELECT Sheet1.F1, Sheet1.F2, Sheet2.F1, Sheet2.F2, Sheet2.F3
FROM Sheet2 RIGHT JOIN Sheet1 ON Sheet2.F3=Sheet1.F3
ORDER BY Sheet2.F3 DESC;
UNION SELECT Sheet1.F1, Sheet1.F2, Sheet2.F1, Sheet2.F2, Sheet2.F3
FROM Sheet2 LEFT JOIN Sheet1 ON Sheet2.F3=Sheet1.F3
ORDER BY Sheet2.F3 DESC;