如何在SQL Server中将多行合并为一行

我有一个执行联合操作的查询。这就是问题所在

SELECT R.ThanaID, R.RoadTypeId, Count(R.Id) AS NoRdExist, 0 AS NoRdImp, 0 AS 
BcLenExist, 0 AS BcLenImp FROM RoadInventory AS R 
        INNER JOIN Thana AS A ON R.ThanaID = A.Id GROUP BY R.ThanaID,R.RoadTypeId 

UNION SELECT R.ThanaID, R.RoadTypeId, 0 AS NoRdExist, Count(R.Id) AS 
NoRdImp,0 AS BcLenExist, 0 AS BcLenImp FROM RoadInventory_Temp AS R
        INNER JOIN Thana AS A ON R.ThanaID = A.Id GROUP BY R.ThanaID, R.RoadTypeId 

UNION SELECT R.ThanaID, RI.RoadTypeId, 0 AS NoRdExist, 0 AS NoRdImp, 
Sum(CASE WHEN(R.SurfaceType='BC') THEN ((R.ToChain-R.FromChain)/1000) END) 
AS BcLenExist, 0 AS BcLenImp
    FROM (RoadInventory AS RI 
        INNER JOIN Thana AS A ON RI.ThanaID = A.Id) 
        INNER JOIN Segment AS R ON (RI.Id = R.RoadID) AND (RI.ThanaID = R.ThanaID) GROUP BY R.ThanaID, RI.RoadTypeId 

UNION SELECT R.ThanaID, RI.RoadTypeId, 0 AS NoRdExist, 0 AS NoRdImp, 0 AS 
BcLenExist, Sum(CASE WHEN(R.SurfaceType='BC') THEN ((R.ToChain-R.FromChain)/1000) END) 
AS BcLenImp
    FROM (RoadInventory_Temp AS RI 
        INNER JOIN Thana AS A ON RI.ThanaID = A.Id) 
        INNER JOIN Segment_Temp AS R ON (RI.Id = R.RoadID) AND (RI.ThanaID = R.ThanaID) GROUP BY R.ThanaID, RI.RoadTypeId 

结果是这样的

ThanaID |RoadTypeId |NoRdExist |NoRdImp |BcLenExist |BcLenImp |
...............................................................
10101   |2          |0         |0       |0          |92
...............................................................
10101   |2          |0         |0       |92         |0
............................................................... 
10101   |2          |0         |8       |0          |0
...............................................................
10101   |2          |8         |0       |0          |0
............................................................... 
10101   |3          |0         |0       |0          |42
...............................................................
10101   |3          |0         |0       |42         |0
...............................................................
10101   |3          |0         |26      |0          |0
...............................................................
10101   |3          |26        |0       |0          |0
...............................................................

现在我想将包含0（零）的列合并到包含值的列中

ThanaID |RoadTypeId |NoRdExist |NoRdImp |BcLenExist |BcLenImp |
...............................................................
10101   |2          |8         |8       |92         |92
............................................................... 
10101   |3          |26        |26      |42         |42
...............................................................

---

如何压缩这些行？

通过ThanaID和RoadTypeID进行Hi分组，然后对字段NoRdExist、NoRdImp、BcLenExist求和 还有b蓝精灵。 试试这个

---

您希望每个ThanaID和RoadTypeId有一个结果行以及其他值的总和。因此，根据您的查询，您可以简单地聚合：

select thanaid, roadtypeid, sum(nordexist), sum(nordimp), sum(bclenexist), sum(bclenimp)
from ( your query here )
group by thanaid, roadtypeid
order by thanaid, roadtypeid;

---

（我可能会以不同的方式编写查询，以便不在单独的行中获取值，但使用上面给出的查询，现在查询是最简单的解决方案。）

您正在根据ThanaID和

RoadTypeId运行不同的查询。然后通过
联合
将它们合并。不清楚您为什么要这样做，因为您似乎对
UNION
结果不感兴趣。似乎您想要一个合并的结果。可能是内部连接，可能是所有查询的完全外部连接；我不知道。下面我展示了所有
ThanaID
和
RoadTypeId
组合的结果，从而避免了完全外部联接，因为在SQL Server中，由于缺少
USING
子句，多个完全外部联接相当笨拙

select
  t.id as thanaid,
  rt.id as roadtypeid,
  q1.nordexist,
  q2.nordimp
from thana t
cross join roadtype rt
left join
(
  select thanaid, roadtypeid, count(*) as nordexist 
  from roadinventory 
  group by thanaid, roadtypeid 
) q1 on q1.thanaid = t.id and q1.roadtypeid = rt.id
left join
(
  select thanaid, roadtypeid, count(*) as nordimp
  from roadinventory_temp 
  group by thanaid, roadtypeid 
) q2 on q2.thanaid = t.id and q2.roadtypeid = rt.id
...

我不知道您的模式，但快速查看一下查询就知道不需要联合。您可能可以在具有多个联接的单个查询中实现这一点。如果没有，则在所需列上使用另一个select with sum函数包装此联合。简单地说，将当前查询包装为CTE，然后通过
ThanaID
聚合，获取所有列的总和。或者，按照@danish的建议，尝试编写一个查询来处理所有问题。旁注：为什么
UNION
而不是简单的
UNION ALL
？我不认为有任何重复的删除，是吗？那你为什么一直在加入
Thana
表呢？你没有用它。谢谢你的建议。你能分享一下你是如何写这个查询的吗？我不能做总和，因为我有一些其他列，其中包含varchart当您的描述和例子是不完整的。它不仅是零，也不是零和它们的和，就像你的例子。对于字符串，您可能只是使用空值来代替零（您也应该将其用于数值），因此您可以只使用
MAX（value
或
MIN（value）
。总之，我发布了另一个答案，它完全避免了联合中间结果。
select
  t.id as thanaid,
  rt.id as roadtypeid,
  q1.nordexist,
  q2.nordimp
from thana t
cross join roadtype rt
left join
(
  select thanaid, roadtypeid, count(*) as nordexist 
  from roadinventory 
  group by thanaid, roadtypeid 
) q1 on q1.thanaid = t.id and q1.roadtypeid = rt.id
left join
(
  select thanaid, roadtypeid, count(*) as nordimp
  from roadinventory_temp 
  group by thanaid, roadtypeid 
) q2 on q2.thanaid = t.id and q2.roadtypeid = rt.id
...