Question

情况：我正在处理的Access数据库将零件分成左右两部分。两侧可以使用相同的部件。我正在尝试创建一个查询来计算每周所需的单个部件的总数。

问题：如何创建允许UNION多个字段和JOIN的查询，如下所示？

Table 1:
Part # |Left Part | Left Part Qty | Right Part | Right Part Quantity
1        xyz         5               lmn          7
2        abc         8               xyz          4

Table 2:
Part # | Needed
1        10
2        25

Query:
Part | Quantity
xyz    150 (5 * 10) + (4 * 25) 
abc    200 (8 * 25) 
lmn    70 (7 * 10)

Answer 1

您在MS Access中遇到问题，因为您无法将union / union all放入子查询中。如果你有一个零件表（你应该有），那么你可以使用left join，所以我认为以下是你想要的：

select p.partname,
       sum(nz(t1l.leftpartqty * t2.needed) + nz(t1r.rightpartqty * t2.needed))
from ((part as p inner join
       table2 as t2
       on p.part# - t2.part# 
      ) left join
      table1 as t1l
      on t1l.leftpart = p.partname 
     ) left join
     table1 as t1r
     on t1r.rightpart = p.partname
group by p.partname;

如果您没有这样的表格，可以使用视图执行union all并从那里开始。

Answer 2

这也应该有效：

SELECT T.Part, SUM(T.Qty * S.Needed) AS Quantity
FROM (
SELECT A.[Part#] AS PartNo, A.LeftPart As Part, A.LeftPartQty As Qty
FROM Table1 AS A
UNION ALL
SELECT B.[Part#] AS PartNo, B.RightPart As Part, B.RightPartQty As Qty
FROM Table1 AS B
) AS T INNER JOIN Table2 AS S ON T.PartNo = S.[Part#]
GROUP BY T.Part
ORDER BY T.Part

结果：

Part    Quantity
abx     200
lmn     70
xyz     150

有关详细信息，请参阅：
UNION (MS Access)
Subqueries (MS Access)
INNER JOIN Operations (MS Access)
LEFT JOIN, RIGHT JOIN Operations (MS Access)

访问UNION和JOIN查询

2 个答案: