SQL 查询，我已加入同一张表，但不同行的值相同

Question

在同一张表下，我必须找到不同字段的总和，所以我使用下面的查询

select db.*, isnull(cb."8",0) as "8", db."PUR Total" - isnull(cb."8",0) as "9", eb.Item1, eb."PO Total"
  from 
  (select b.t_dicl as Department, c.t_item as Item, sum( c.t_qstk )as "8"
  from inforlndb.dbo.twhinr1109980 AS c INNER JOIN inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
  where c.t_koor = 2 and c.t_kost = 3 and month(c.t_trdt) <= @aMonth - 1
  group by c.t_item, b.t_dicl) as cb
full outer join
    (select b.t_dicl as Department, c.t_item as Item, sum( c.t_qstk )as "PUR Total"
    from inforlndb.dbo.twhinr1109980 AS c INNER JOIN     inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
    where c.t_koor = 2 and c.t_kost = 3 and month(c.t_trdt) <= @aMonth
    group by c.t_item, b.t_dicl) as db
    on cb.Item = db.Item
--Production order
full outer join
    (select b.t_dicl as Department, c.t_item as Item, sum( c.t_qstk )as "8"
  from inforlndb.dbo.twhinr1109980 AS c INNER JOIN inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
  where c.t_koor = 1 and c.t_kost = 5 and month(c.t_trdt) <= @aMonth - 1
  group by c.t_item, b.t_dicl) as ab
  on cb.Item = ab.Item
full outer join
(select b.t_dicl as Department, c.t_item as Item1, sum( c.t_qstk )as "PO Total"
    from inforlndb.dbo.twhinr1109980 AS c INNER JOIN inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
     where c.t_koor = 1 and c.t_kost = 5 and month(c.t_trdt) <= @aMonth
    group by c.t_item, b.t_dicl) as eb
    on cb.Item = eb.Item1

样本输出为

Department  Item    PUR Total   8   9       Item1       PO Total
EV           G00046301  25000   0   25000   NULL        NULL
EV           G00053001  10000   10000   0   G00053001   55
EV           G00251701  4500    4500    0   G00251701   220
TF           G01259901  200 0   200 NULL    NULL
NULL        NULL        NULL    0   NULL    NG707460AS  5
NULL        NULL        NULL    0   NULL    G00046301   72
NULL        NULL        NULL    0   NULL    G02280100   6
NULL        NULL        NULL    0   NULL    NG707460BS  5

从输出中，您可以看到列 Item 和 Item1 下的不同行有两个相同的数据。如何合并它们？

抱歉代码比较乱，我还在学习中=="

Answer 1

中间的两个部分是连接 Item 到 Item，而不是 Item 到 Item1。 Item 到 Item1 仅在最终连接中发生。在您的顶部选择列表中，我们有 db.Item（来自第二个表）和 eb.Item1（来自最后一个表）。查看 Item G00046301 我们看到它存在于 db 表中，但要让它在 eb 表中找到它的匹配项，我们需要：

db.Item -> ab.Item -> eb.Item1

中间表 (ab) 不能有 G00046301 的行。因为这些是完全外连接，所以当中间链接丢失但最后的表找不到匹配时，我们仍然会得到结果。所以……

由于您的选择似乎更关心 db 和 ab，您可以尝试像这样直接加入它们：

select db.*, isnull(cb."8",0) as "8", db."PUR Total" - isnull(cb."8",0) as "9", eb.Item1, eb."PO Total"
  from 
  (select b.t_dicl as Department, c.t_item as Item, sum( c.t_qstk )as "8"
  from inforlndb.dbo.twhinr1109980 AS c INNER JOIN inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
  where c.t_koor = 2 and c.t_kost = 3 and month(c.t_trdt) <= @aMonth - 1
  group by c.t_item, b.t_dicl) as cb
full outer join
    (select b.t_dicl as Department, c.t_item as Item, sum( c.t_qstk )as "Total"
    from inforlndb.dbo.twhinr1109980 AS c INNER JOIN     inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
    where c.t_koor = 2 and c.t_kost = 3 and month(c.t_trdt) <= @aMonth
    group by c.t_item, b.t_dicl) as db
    on cb.Item = db.Item
--Production order
full outer join
    (select b.t_dicl as Department, c.t_item as Item, sum( c.t_qstk )as "8"
  from inforlndb.dbo.twhinr1109980 AS c INNER JOIN inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
  where c.t_koor = 1 and c.t_kost = 5 and month(c.t_trdt) <= @aMonth - 1
  group by c.t_item, b.t_dicl) as ab
  on cb.Item = ab.Item
full outer join
(select b.t_dicl as Department, c.t_item as Item1, sum( c.t_qstk )as "Total"
    from inforlndb.dbo.twhinr1109980 AS c INNER JOIN inforlndb.dbo.ttcemm1129980 AS b ON  b.t_waid = c.t_cwar
     where c.t_koor = 1 and c.t_kost = 5 and month(c.t_trdt) <= @aMonth
    group by c.t_item, b.t_dicl) as eb
    on db.Item = eb.Item1

唯一的变化是最后一行

    on db.Item = eb.Item1

我希望这会有所帮助。