多表数据加减问题
有以下两个查询语句
SELECT Item_code, SUM(in_qty) AS sum1
FROM in_TTBL
WHERE (indate > = DATEADD(mm, DATEDIFF(mm, 0, GETDATE()), 0))
GROUP BY Item_code
ORDER BY Item_code
SELECT Item_code, SUM(out_qty) AS sum2
FROM out_TTBL
WHERE (outdate > = DATEADD(mm, DATEDIFF(mm, 0, GETDATE()), 0))
GROUP BY Item_code
ORDER BY Item_code
我希望item_code相同的sum1和sum2相加或相减用一句sql语句实现，请帮帮忙，谢谢！
[解决办法]
Select A.Item_code, A.sum1 + B.sum2 As sum3
From
(SELECT Item_code, SUM(in_qty) AS sum1
FROM in_TTBL
WHERE (indate > = DATEADD(mm, DATEDIFF(mm, 0, GETDATE()), 0))
GROUP BY Item_code
) A
Inner Join
(
SELECT Item_code, SUM(out_qty) AS sum2
FROM out_TTBL
WHERE (outdate > = DATEADD(mm, DATEDIFF(mm, 0, GETDATE()), 0))
GROUP BY Item_code
) B
On A.Item_code = B.Item_code
