如何将A,B两表中的数据汇总到一张表上

SELECT a.岗位分类, Sum(a.a) AS 个人缴纳合计, Sum(a.b) AS 单位缴纳合计
FROM (SELECT tbl1.岗位分类, tbl1.Q0002汇总岗位分类（正式工）个人缴纳之合计 as a, tbl1.公司缴纳之合计 as b
FROM tbl1
WHERE (((tbl1.岗位分类)<>""))
UNION ALL SELECT tbl1.岗位分类, tbl1.Q0004汇总岗位分类（协力工）个人缴纳之合计, tbl1.单位缴纳之合计
FROM tbl1
WHERE (((tbl1.岗位分类)<>""))
)  AS a
GROUP BY a.岗位分类
union all
SELECT "合计",Sum(a.a) AS a之合计, Sum(a.b) AS b之合计
FROM (SELECT tbl1.岗位分类, tbl1.Q0002汇总岗位分类（正式工）个人缴纳之合计 as a, tbl1.公司缴纳之合计 as b
FROM tbl1
WHERE (((tbl1.岗位分类)<>""))
UNION ALL SELECT tbl1.岗位分类, tbl1.Q0004汇总岗位分类（协力工）个人缴纳之合计, tbl1.单位缴纳之合计
FROM tbl1
WHERE (((tbl1.岗位分类)<>""))
)  AS a;