>>>SELECT tmp.mcat_code, tmp.mat_code, Mat.mcat_desc, Mat.mat_desc, SUM(tmp.qty) AS qty >>>FROM (SELECT mcat_code, mat_code, SUM(qty) AS qty >>> FROM mat_ob >>> GROUP BY mcat_code, mat_code >>> UNION >>> SELECT mcat_code, mat_code, SUM(qty) AS qty >>> FROM Purchase >>> GROUP BY mcat_code, mat_code >>> UNION >>> SELECT mcat_code, mat_code, SUM((con_qty + wst_qty) * - 1) AS qty >>> FROM Production >>> GROUP BY mcat_code, mat_code ) AS tmp INNER JOIN >>> Mat ON Mat.mcat_code + Mat.mat_code = tmp.mcat_code + tmp.mat_code >>>GROUP BY tmp.mcat_code, tmp.mat_code, Mat.mcat_desc, Mat.mat_desc >>>ORDER BY tmp.mcat_code, Mat.mat_desc >>>>>>