我的数据看起来像:
OrderID CustomerID ItemID ItemName
10000 1234 111111 Product A
10000 1234 222222 Product B
10000 1234 333333 Product C
20000 5678 111111 Product A
20000 5678 222222 Product B
20000 5678 333333 Product C
我想在SQL Server中编写一个T-SQL查询来返回如下数据:
<Root>
<Order>
<OrderID>10000</OrderID>
<CustomerID>1234</CustomerID>
<LineItem>
<ItemID>11111</ItemId>
<ItemName>Product A</ItemName>
</LineItem>
<LineItem>
<ItemID>22222</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
<LineItem>
<ItemID>33333</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
</Order>
<Order>
<OrderID>20000</OrderID>
<CustomerID>5678</CustomerID>
<LineItem>
<ItemID>11111</ItemId>
<ItemName>Product A</ItemName>
</LineItem>
<LineItem>
<ItemID>22222</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
<LineItem>
<ItemID>33333</ItemId>
<ItemName>Product B</ItemName>
</LineItem>
</Order>
</Root>
我尝试使用以下方法在XML中返回查询:
FOR XML PATH ('Order'), root ('Root')
但是这给了我一个Order
节点,每行(总共6个),而不是每个orderId
的订单节点(总共2个)。
有什么想法吗?
答案 0 :(得分:30)
select
OrderID,
CustomerID,
(
select
ItemID,
ItemName
from @Orders rsLineItem
where rsLineItem.OrderID = rsOrders.OrderID
for xml path('LineItem'), type
)
from (select distinct OrderID, CustomerID from @Orders) rsOrders
FOR XML PATH ('Order'), root ('Root')
答案 1 :(得分:3)
完成:这是一个没有subselect的解决方案,应该对大表执行得更快。相反,它将表格分组的次数与XML中的级别一样多,并使用GROUPING_ID标识级别(请参阅https://technet.microsoft.com/en-us/library/bb522495(v=sql.105).aspx和https://docs.microsoft.com/en-us/sql/relational-databases/xml/use-explicit-mode-with-for-xml):
with rsOrders as (
select '10000' OrderID, '1234' CustomerID, '111111' ItemID, 'Product A' ItemName union
select '10000' orderId, '1234' customerID, '222222' itemID, 'Product B' ItemName union
select '10000' orderId, '1234' customerID, '333333' itemID, 'Product C' ItemName union
select '20000' orderId, '5678' customerID, '111111' itemID, 'Product A' ItemName union
select '20000' orderId, '5678' customerID, '222222' itemID, 'Product B' ItemName union
select '20000' orderId, '5678' customerID, '333333' itemID, 'Product C' ItemName
)
select case
when GROUPING_ID(ItemID) = 0 then 3
when GROUPING_ID(OrderID) = 0 then 2
else 1
end as tag,
case
when GROUPING_ID(ItemID) = 0 then 2
when GROUPING_ID(OrderID) = 0 then 1
else null
end as parent,
null as 'Root!1',
OrderID as 'Order!2!OrderID!element',
CustomerID as 'Order!2!CustomerID!element',
ItemID as 'LineItem!3!ItemID!element',
ItemName as 'LineItem!3!ItemName!element'
from rsOrders
group by grouping sets ((), (OrderID, CustomerID), (OrderID, CustomerID, ItemID, ItemName))
order by OrderID, CustomerID, ItemID, ItemName
for xml explicit, type