Задачи для обучения SQL-запросам в Супермаге : Программирование

DECLARE I PLS_INTEGER; ' + #13 +
        'BEGIN ' + #13 + 
        '  FOR c IN (SELECT doctype, docid, specitem, itemprice ' + #13 + 
        '            FROM supermag.smspec ' + #13 + 
        '            WHERE doctype = ''WI'' AND docid = ''' + paramDocID + ''') ' + #13 +
        '  LOOP ' + #13 +
        '    BEGIN ' + #13 + 
        '      SELECT count(*) INTO I FROM supermag.smspecby WHERE doctype = c.doctype AND docid = c.docid AND specitem = c.specitem; ' + #13 +
        '      IF I = 0 THEN ' + #13 + 
        '        INSERT INTO supermag.smspecby(doctype, docid, specitem, manufacturersprice, extracharge, retailprice) ' + #13 +
        '        VALUES(c.doctype, c.docid, c.specitem, c.itemprice, 0, c.itemprice); ' + #13 +
        '      ELSE ' + #13 + 
        '        UPDATE supermag.smspecby ' + #13 +
        '        SET manufacturersprice = c.itemprice, extracharge = 0, retailprice = c.itemprice ' + #13 +
        '        WHERE doctype = c.doctype AND docid = c.docid AND specitem = c.specitem; ' + #13 +
        '      END IF; ' + #13 +
        '      COMMIT; ' + #13 +
        '    EXCEPTION WHEN OTHERS THEN NULL; ' + #13 +
        '    END; ' + #13 +
        '  END LOOP; ' + #13 +
        'END;'

FOR c IN (SELECT doctype, docid, specitem, itemprice ' + #13 + 
        '            FROM supermag.smspec ' + #13 + 
        '            WHERE doctype = ''WI'' AND docid = ''' + paramDocID + ''')

ELSE ' + #13 + 
        '        UPDATE supermag.smspecby ' + #13 +
        '        SET manufacturersprice = c.itemprice, extracharge = 0, retailprice = c.itemprice ' + #13 +
        '        WHERE doctype = c.doctype AND docid = c.docid AND specitem = c.specitem;