FROM 子句中的子查询导致 FOR XML AUTO 输出中不需要的 ELEMENT

Question

我正在使用 Northwind 为 SQL 建模，我相信我需要使用我的实际数据来构建 Google 地图应用程序。我认为我的查询工作正常，但在 XML 中返回时，层次结构不是我需要的方式。

SELECT   Marker.CustomerID
    ,Marker.CompanyName
    ,Marker.TotalAmount
    ,o.OrderID
    ,o.Freight
FROM     
    (
            SELECT   c.CustomerID
            ,c.CompanyName
            ,c.Address
            ,COUNT(o.freight) as TotalOrders
            ,SUM(o.freight) as TotalAmount
            FROM     Customers c
             INNER JOIN Orders o
               ON c.CustomerID = o.CustomerID
                where c.CustomerID = 'ALFKI' or c.CustomerID = 'ANTON'
                group by c.CustomerID
                        ,c.CompanyName
                        ,c.Address
    ) AS Marker                         

     INNER JOIN Orders o
       ON Marker.CustomerID = o.CustomerID
where Marker.CustomerID = 'ALFKI' or Marker.CustomerID = 'ANTON'
order by 1
for xml auto, root('root')

这是返回的 XML：

<root>
<c CustomerID="ALFKI" CompanyName="Alfreds Futterkiste">
 <Marker TotalAmount="225.5800">
  <o OrderID="10643" Freight="29.4600" />
  <o OrderID="10692" Freight="61.0200" />
  <o OrderID="10702" Freight="23.9400" />
  <o OrderID="10835" Freight="69.5300" />
  <o OrderID="10952" Freight="40.4200" />
  <o OrderID="11011" Freight="1.2100" />
 </Marker>
</c>
<c CustomerID="ANTON" CompanyName="Antonio Moreno Taquería">
 <Marker TotalAmount="268.5200">
  <o OrderID="10365" Freight="22.0000" />
  <o OrderID="10507" Freight="47.4500" />
  <o OrderID="10535" Freight="15.6400" />
  <o OrderID="10573" Freight="84.8400" />
  <o OrderID="10677" Freight="4.0300" />
  <o OrderID="10682" Freight="36.1300" />
  <o OrderID="10856" Freight="58.4300" />
 </Marker>
</c>
</root>

使用 c 作为 customers table 的别名的子查询在 XML 中是不需要的；然而，我似乎需要它，因为 CustomerID 在订单和客户中都是模棱两可的。我想知道如何在 Marker 中仅显示 o，如下图所示：

<root>
<Marker CustomerID="ALFKI" CompanyName="Alfreds Futterkiste" TotalAmount="225.5800">
  <o OrderID="10643" Freight="29.4600" />
  <o OrderID="10692" Freight="61.0200" />
  <o OrderID="10702" Freight="23.9400" />
  <o OrderID="10835" Freight="69.5300" />
  <o OrderID="10952" Freight="40.4200" />
  <o OrderID="11011" Freight="1.2100" />
</Marker>

Answer 1

用cte怎么样

WITH Marker AS (
    SELECT   c.CustomerID
    ,c.CompanyName
    ,c.Address
    ,COUNT(o.freight) as TotalOrders
    ,SUM(o.freight) as TotalAmount
    FROM     Customers c
     INNER JOIN Orders o
       ON c.CustomerID = o.CustomerID
        where c.CustomerID = 'ALFKI' or c.CustomerID = 'ANTON'
        group by c.CustomerID
                ,c.CompanyName
                ,c.Address
)
SELECT   Marker.CustomerID
,Marker.CompanyName
,Marker.TotalAmount
,o.OrderID
,o.Freight
FROM  Marker                         
INNER JOIN Orders o
   ON Marker.CustomerID = o.CustomerID
where Marker.CustomerID = 'ALFKI' or Marker.CustomerID = 'ANTON'
order by 1
for xml auto, root('root')

Answer 2

通常，我一直认为在 OP 中使用子查询有点 "cooler" 但正如所评论的那样，@DVT 的 CTE 想法产生了相同的 XML 所以我重写如下.通过避免子查询并填充临时 table，我能够根据需要获取 XML 层次结构中的元素：

CREATE TABLE #TempMarkers
(
    CustomerID nchar(5) NOT NULL,
    CompanyName nvarchar(40) NOT NULL,
    Address nvarchar(60) NULL,
    TotalOrders int NULL,
    TotalAmount money NULL
)
INSERT INTO #TempMarkers
(CustomerID
,CompanyName
,Address
,TotalOrders
,TotalAmount
)
SELECT  c.CustomerID
        ,c.CompanyName
        ,c.Address
        ,COUNT(o.freight) as TotalOrders
        ,SUM(o.freight) as TotalAmount
        FROM     Customers c
         INNER JOIN Orders o
           ON c.CustomerID = o.CustomerID
            where c.CustomerID = 'ALFKI' or c.CustomerID = 'ANTON'
            group by c.CustomerID
                    ,c.CompanyName
                    ,c.Address
SELECT   Marker.CustomerID
        ,Marker.CompanyName
        ,Marker.TotalAmount
        ,Marker.TotalOrders
        ,o.OrderID
        ,o.Freight
FROM #TempMarkers Marker     
     INNER JOIN Orders o
       ON Marker.CustomerID = o.CustomerID
where Marker.CustomerID = 'ALFKI' or Marker.CustomerID = 'ANTON'
order by 1
for xml auto, root('root')

FROM 子句中的子查询导致 FOR XML AUTO 输出中不需要的 ELEMENT

Subquery in FROM clause is causing unwanted ELEMENT in FOR XML AUTO output

tsql

sql-server

subquery

sql-server-2008

select-for-xml